Answer:
As the marble starts rolling down the roller coaster, the amount of potential energy stored in the marble decreases while its kinetic energy increases. Potential energy is also converted into heat energy due to friction.
Explanation:
As the marble rolls down the hill its potential energy is converted to kinetic energy (its height decreases, but its velocity increases). When the marble goes back up the loop its height increases again and its velocity decreases, changing kinetic energy into potential energy.
The two (2) ways in which the potential energy of a marble on a ramp can be increased are:
I. By placing the marble higher on the ramp.
II. By increasing the mass of the marble.
Potential energy can be defined as a type of energy possessed by an object (body) as a result of its position (height) above the earth.
Mathematically, potential energy (P.E) is calculated by using the following formula:
[tex]P.E = mgh[/tex]
Where:
m is the mass of an object. g is the acceleration due to gravity. h is the height of an object.Hence, potential energy (P.E) is highly dependent on two (2) main factors and these are:
1. Height above the ground.
2. The mass of an object.
In conclusion, the two (2) ways in which the potential energy of a marble on a ramp can be increased are:
Increasing the height of the marble, by placing the marble higher on the ramp.By increasing the mass of the marble such as adding more marbles.Read more: https://brainly.com/question/23153766
One normal afternoon in undisclosed City X, the chocolate factory workers overload the Easter egg machine. A group of angsty teens cutting school at the edge of City X see a large explosion from across town as the factory explodes, covering the rooftops in unrefined sugars. Five seconds later, they hear the boom. Approximately how far are they from the factory? show work
A. 68.6 m
B. 145 m
C. 1,715 m
D. 60,000 m
Answer:
The correct option is;
C. 1,715 m
Explanation:
We are given the information from the group of teen at the City edge
Time of arrival of explosion sound = 5 s after sighting
Time of sighting explosion = 5 s before hearing the boom
Speed of sound in air ≈ 343 m/s
Speed of light = 299,792 km/s
Therefore, distance covered by sound in 5 seconds is given by the following equation;
[tex]Speed = \frac{Distance}{Time}[/tex]
[tex]\therefore 343 \ m/s= \frac{Distance}{5 \, s}[/tex]
Hence Distance = 343 m/s × 5 s = 1715 m
To check, we compare the time it would take for the light to cover 1715 m
That is [tex]Time = \frac{Distance}{Speed} = \frac{1715}{299,792,000} = 0.00000572 \, s[/tex] which is instantaneous hence the distance can be approximated by the time duration for the speed of sound.
Therefore, the distance of the students from the factory is approximately 1,715 m
Using the speed of sound at 24.0°C, which is roughly 343 m/s, and knowing the sound took 5 seconds to reach the observers, the calculated distance to the explosion is 1715 meters.
The question involves calculating the distance from an observed event based on the speed of sound, which falls under the subject of Physics. To determine how far the teens are from the factory, we can use the speed of sound, which depends on air temperature. Given the standard temperature of 24.0°C, the speed of sound in air is approximately 343 meters per second. The explosion sound reached the teens 5 seconds after they saw it, meaning the sound traveled for 5 seconds to reach them.
The distance can be calculated using the formula: distance = speed x time. Plugging in the values: distance = 343 m/s x 5 s = 1715 meters. Therefore, the teens were approximately 1715 meters away from the factory when they heard the explosion.
A changing current in one loop of wire can induce a current in another loop of wire even though the wires do not touch. The induced current appears almost instantaneously for loops close together. How can this energy exchange happen?
Answer:
It is done via an electromagnetic wave.
Explanation:
According to the concept of length contraction, what happens to the length of an object as it approaches the speed of light and then slows down, eventually coming to a stop?
Answer:
It contracts and returns to its original length when it stops.
Explanation:
As it approaches the speed of light, the length of the object is observed to contract. Then as it comes to a stop, it returns back to its original length.
Write a nuclear equation to describe the neutron induced fission of u-235 to form xe-134 and sr-100. Determine how many neutrons are produced in the reaction.
Answer:
The nuclear equation is give as [tex]\ce{^{235}_{92}U} + \ce{^{1}_{0}n} \rightarrow \ce{^{134}_{54}Xe} + \ce{^{100}_{38}Sr} + 2 (\ce{^{1}_{0}n})[/tex]
The number of neutrons produced = 2
Explanation:
Since the reaction is a neutron induced fission of Uranium, a certain amount of neutron will be emitted with Xe - 34 and Sr - 100
Therefore the nuclear equation is given as:
[tex]\ce{^{235}_{92}U} + \ce{^{1}_{0}n} \rightarrow \ce{^{134}_{54}Xe} + \ce{^{100}_{38}Sr} + y (\ce{^{1}_{0}n})[/tex]
To get the value of y:
Sum of mass numbers at the reactant = Sum of mass numbers at the product
235 + 1 = 134 + 100 + y
y = 236 - 234
y = 2
Therefore, the nuclear equation above becomes:
[tex]\ce{^{235}_{92}U} + \ce{^{1}_{0}n} \rightarrow \ce{^{134}_{54}Xe} + \ce{^{100}_{38}Sr} + 2 (\ce{^{1}_{0}n})[/tex]
As seen from the equation above, the number of neutrons produced in the reaction = 2
The nuclear equation for the neutron-induced fission of U-235 to form Xe-134 and Sr-100 is 235U + 1n → 134Xe + 100Sr + xn. The number of neutrons produced in the reaction can vary, but it is typically two or three.
Explanation:The nuclear equation to describe the neutron-induced fission of U-235 to form Xe-134 and Sr-100 is:
235U + 1n → 134Xe + 100Sr + xn
Here, xn represents the number of neutrons produced in the reaction. The exact value of xn depends on the specific reaction and can vary. In general, the fission of U-235 produces two or three neutrons, each of which is capable of causing the fission of another nucleus.
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You see an image of yourself in a mirror because light waves are A) diffracted. B) reflected back at you. C) refracted through air. D) refracted to a focal point.
Answer:
(b) reflected back at you
Explanation:
Answer:
B) Reflected back at you.
Explanation:
Because of the smooth surface light reflects and bounces back to you making you see a reflected image of your self.
Hope this helped! Good luck and stay safe!!
What is the definition for Astrology?
Astrology is a belief system which posits that the positions and movements of celestial bodies (the Sun, Moon, and planets) can influence human affairs and natural phenomena. Astrological practices involve the creation of horoscopes, which are detailed charts calculated based on the exact time, date, and location of an individual's birth, with the intention of gaining insight into personality traits, relationships, and life events.
The origins of astrology are rooted in ancient civilizations and can be traced back thousands of years. Early forms of astrology were used by the Babylonians as a method for predicting seasonal shifts and interpreting celestial cycles as omens. Horoscopes, central to natal astrology, detail the positions of the planets within the zodiac at the moment of one's birth, aiming to provide guidance or predictions. Critiques of astrology as a scientific practice point to a lack of empirical evidence and reproducibility, the Forer effect (subjects giving high accuracy ratings to vague and general personality descriptions), and the logical inconsistencies within astrological traditions which discredit its validity as a science.
An areoplane initially at rest, undergoes a constant acceleration on of 2.5m/second down the runway for 30sec before taking off
Answer:
I'll just assume that the question is what's the velocity of the airplane before it takes off because you haven't included a question. Where u: velocity, a: acceleration, t: time
[tex]u = a \times t \\ u = 2.5 \times 30 \\ u = 70ms[/tex]
Stacy begins by hanging metal washers from a force meter. Then she measures the downward pull on the washers. What
force causes this downward pull?
The Answer is:
Weight
(hope that helped)
Answer:
Earth’s gravity causes the downward pull on the washers.
Explanation:
This is the sample answer on Edmentum. :)
Please, help!!
Three equal point charges of 4.00 nC lie 4.00 m apart on
a line. Calculate the magnitude and direction of the net
force on the middle charge.
Answer:
The net force in the middle particle is zero, and it has no direction.
Explanation:
First, the force that one charge does in other charge is:
F = K*q1*q2/r^2
where k is a constant, q1 and q2 are the charges, and r is the distance between the charges.
If the force is positive, the force is repulsive (pushes away the charge) if the force is negative, is attractive.
Now, we have that the middle charge has a charge of 4.00nC, and in each side at a distance of 4m, has a charge of 4.00nC.
i will write qL as the charge in the left, qR as the charge in the right, and qM as the charge in the middle.
The force that the charge in the right does to the charge in the middle is:
Fr = (k*(4.00nC)^2)/4m^2 = k*(nC/m)^2
And is positive, so this is a repulsive force, this means that if the charge is at the right of the middle charge, then this force pushes the middle charge to the left.
For the left charge we have the same:
Fl = (k*(4.00nC)^2)/4m^2 = k*(nC/m)^2
But in this case, the force pushes the particle to the right, then this force, that is equal in magnitude to the previous force, pushes it in the opposite direction, then the total force in the middle particle is anulated. This is because the two external particles are "pushing" the middle particle with the same force and in the opposite direction.
The net force in the middle particle is zero, and it has no direction.
What is Force?[tex]F = K*q_1*q_2/r^2[/tex]
where,
k is a constant,
q1 and q2 are the charges, and
r is the distance between the charges.
If the force is positive, the force is repulsive (pushes away the charge) if the force is negative, is attractive.
Given :
Charge = 4.00nC
Distance = 4.00m
The force that the charge in the right does to the charge in the middle is:
[tex]F_r = (k*(4.00nC)^2)/4m^2\\\\F_r = k*(nC/m)^2[/tex]
And is positive, so that is a repulsive pressure, because of this if the charge is on the proper of the center fee, then this pressure pushes the center fee to the left.
For the left charge we have the same:
[tex]F_l = (k*(4.00nC)^2)/4m^2 \\\\F_l = k*(nC/m)^2[/tex]
But on this case, the pressure pushes the particle to the right, then this pressure, this is same in importance to the preceding pressure, pushes it within side the contrary direction, then the entire pressure within side the center particle is annulated. This is due to the fact the 2 outside debris are "pushing" the center particle with the identical pressure and within side the contrary direction.
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A heat engine is a device that uses _____to produce useful work.
A heat engine is a device that uses heat to produce useful work.
Answer:
Heat
Explanation:
A student decides to go to the kitchen for a late night snack. When opening the door, she notices the light from inside seem to cover more floor than the open door. Which wave behavior have they experienced?
a) Diffraction
b) Refraction
c) Reflection
d) Interference
Answer:
diffraction
Explanation:
A 10.0-cm-long wire is pulled along a U-shaped conducting rail in a perpendicular magnetic field. The total resistance of the wire and rail is 0.300 Ω . Pulling the wire at a steady speed of 4.00 m/s causes 3.90 W of power to be dissipated in the circuit.
Question:
What are the magnitudes of the pulling force and the magnetic field
Answer:
The magnetic field strength is 2.7 T
The pulling force [tex]F_p[/tex] is 0.975 N
Explanation:
Here we have;
Length of wire, l = 10.0 cm = 0.1 m
Resistance of wire, R = 0.300 Ω
Speed of wire, v = 4.00 m/s
Power dissipated = 3.90 W
Based on the given data, we apply the relation;
[tex]I =\frac{Blv}{R}[/tex]..............(1)
Where:
B = Magnetic field strength
I = Current
Since P = I²R, we have;
3.9 = I²·0.300Ω
∴ I² = 3.9/0.300 = 13
From which I = √13
Substituting the value of I in equation (1) above, we have;
[tex]\sqrt{13}= \frac{B \times 10.0 \times 4.00}{0.300}[/tex]
Therefore;
[tex]B = \frac{\sqrt{13} \times 0.300}{0.1 \times 4.00} = 2.70416 \ T\approx 2.7 \ T[/tex]
The magnitude of the pulling force is given by the following relation;
[tex]F_p = F_m = IlB = l\sqrt{\frac{P}{R} } \frac{\sqrt{PR} }{lv} =\frac{P}{v} = \frac{3.9 \ W}{4.00 \ m/s} = 0.975 \ N[/tex]
The pulling force [tex]F_p[/tex] = 0.975 N.
HELP ASAP
___________ describes the specific genetic makeup of a living thing and cannot be observed.
Genotypes describe the specific genetic makeup of a living thing and cannot be observed.
Genotypes represent the combination of alleles or genes that an organism possesses for a particular trait or set of traits. They are responsible for determining the inherited characteristics and potential traits that an organism can exhibit.
They can vary for different traits within an individual organism or across different individuals within a species. They play a fundamental role in genetics and inheritance, as they determine the genetic information that is passed from one generation to the next.
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Object B has a mass of 10 kg. Object B collides with another
object. If the momentum of object B after the collision is
18 kg.m/s 18 kg.m/s, its velocity is m/s.
Answer:
1.8m/s
Explanation:
We know that the momentum of an impact of a body is the mass times he velocity
M= mv
Given data
Mass m= 10kg
Momentum M= 18 kg.m/s
Velocity v=?
We can solve for velocity by submitting our given data in the momentum equation
18 = 10*v
v= 18/10
v= 1.8m/s
Answer: 1.8m/s
Explanation: bigger brain
Which best describes the energy of a sound wave as it travels through a medium
a. it remains the same
b. It increases.
c. It depends on the medium
d. it decreases
The energy of a sound wave as it travels through a medium decreases
What is energy of a sound wave ?It is the physical vibration waves that travel through the air to reach the ears . Sound energy is the result when force makes an object vibrate.
A wave can lose energy as it travel through a medium because medium can also absorb the energy . The medium changes some of the acoustic energy of the sound wave into heat .
correct option is d) it decreases
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The energy of a sound wave decreases as it propagates through a medium due to damping, which lessens the amplitude of the wave. The decrease happens because the energy is dispersed over a growing area and is absorbed by the medium.
Explanation:The question asks which best describes the energy of a sound wave as it travels through a medium. The correct answer is that the energy of a sound wave decreases as it propagates through a medium. This decrease in energy is due to damping, which is an effect that decreases the amplitude of the wave as it travels. Damping occurs because the energy of the sound wave is spread out over an increasingly larger area and is absorbed by the medium.
Factors Affecting Sound Wave PropagationThe amplitude of a sound wave decreases with distance from its source.When a sound wave enters a medium where its speed increases, the wavelength also increases, but the speed of sound primarily depends on the properties of the medium, not the amplitude or wavelength.The energy of a sound wave is affected by the medium through which it travels, with factors like damping leading to a decrease in energy.The average force of a baseball is 18.9 N . It’s mass is 0.145kg fine the acceleration in m/s^2
Answer:
the acceleration is 130.3m/s²
Explanation:
Given data
Force F= 18.9N
Mass of ball m= 0.145kg
Acceleration a=?
Applying the Newton's second law of motion
"The rate of change of momentum of a body is proportional to the external force".
F=ma
a= F/m
a= 18.9/0.142
a= 130.3m/s²
The acceleration of the baseball is 130.35 [tex]m/s^2[/tex].
Given the following data:
Average force of a baseball = 18.9 NewtonMass of baseball = 0.145 KilogramsTo find the acceleration of the baseball, we would apply Newton's Second Law of Motion:
Mathematically, Newton's Second Law of Motion is given by this formula;
[tex]Acceleration = \frac{Force}{Mass}[/tex]
Substituting the given values, we have;
[tex]Acceleration = \frac{18.9}{0.145}[/tex]
Acceleration = 130.35 [tex]m/s^2[/tex]
Therefore, the acceleration of the baseball is 130.35 [tex]m/s^2[/tex].
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As the resistance increased under 25 V, the current blank. Compared to calculated currents, experimental currents proved to be blank . Currents varied proportionally according to resistance: 10 Ω of resistance produced a current of blank A, while 100 Ω of resistance produced a current of blank A.
Answer:
Decreased, The Same, 2.5 and .25
Explanation:
A student is asked to design a cart that will have the smallest force of impact when it collides with another object. Which of these would be the best design
Answer:D
Explanation:
Because I got it wrong
Which event happens as the amplitude of a light wave increases?
A. The light appears more violet.
B. The light appears dimmer.
C. The light appears brighter.
D. The light appears more red.
Answer:
C. The light appears brighter
Explanation:
As the amplitude of a light wave increases, the light appears brighter.
What is amplitude?The amplitude is the vertical distance from the axis of the sinusoidal wave at a particular time.
When the amplitude of a wave is increased, its energy is increased. Energy of the wave is directly proportional to the square of the amplitude. Energy is actually the intensity of the wave.
Thus, as the amplitude of a light wave increases, the light appears brighter.
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What kind of magnets are shown in the figure above?
Answer:
Electromagnets.
Explanation:
They acquire their magnetism by flow of current and electromagnetic induction
The kind of magnet that should be shown in the figure is electromagnet.
What is an electromagnet?An electromagnet refer to the type of magnet where the magnetic field is generated via an electric current. It comprise of wire wound into a coil. A current via the wire develops a magnetic field i.e. concentrated in the hole, represents the center of the coil. Also, it acquire their magnetism with the help of flow of current and electromagnetic induction.
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Please help :( A ray of laser light strikes a glass surface at an angle θa = 22.5° to the normal. What is the angle θb of the refracted ray? Let the index of refraction for glass nb = 1.77 (you are able to choose two)
A 12.5°
B 12.7°
C 10.1°
D 31.8°
Answer:
Explanation:
We shall apply law of refraction which is as follows
sin i / sinr = μ , where i is angle of incidence , r is angle of refraction and μ is refractive index
here i = θa = 22.5°
r = θb
μ = 1.77
sin22.5 / sinθb = 1.77
.3826 / sinθb = 1.77
sinθb = .216
θb = 12.5 °.
How are sound waves reflected, transmitted, or absorbed by materials?
which of the following best describes each particle?
A. Protons are negative, neutrons are neutral, and electrons are positive.
B. Protons are neutral, neutrons are positive, and electrons are negative.
C. Protons are positive, neutrons are neutral, and electrons are negative.
D. Protons are neutral, neutrons are negative, and electrons are positive.
Answer:
C. Protons are positive, neutrons are neutral, and electrons are negative
The description that correctly labels each particle's charge is option C: Protons are positive, neutrons are neutral, and electrons are negative. These particles compose the anatomy of an atom.
Explanation:The question asks for the correct assignment of charges to particles that make up atoms. The best description for each particle is given by option C. Here, protons are correctly labeled as positive, neutrons as neutral, and electrons as negative. In an atom, protons and neutrons reside in the nucleus (the center), while electrons occupy space around the nucleus, in what's known as electron clouds or shells.
Understanding the correct assignment of charges to atomic particles is fundamental in grasping the structure of atoms. Protons, carrying a positive charge, and neutrons, which are neutral, are concentrated in the nucleus, forming the central core. Meanwhile, electrons, negatively charged, orbit the nucleus in electron clouds or shells, contributing to the overall electrical balance of the atom.
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The function s(t) = vt + h – 0.5at2 represents the height of an object, s, in feet, above the ground in relation to the time, t, in seconds, since the object was thrown into the air with an initial velocity of v feet per second at an initial height of h feet and where a is the acceleration due to gravity (32 feet per second squared). A baseball player hits a baseball 5 feet above the ground with an initial velocity of 70 feet per second. About how long will it take the baseball to hit the ground? A) 2 seconds B) 3 seconds C) 4 seconds D) 5 seconds
Answer:
C) 4 seconds
Explanation:
The height of an object is given by the following formula:
[tex]s(t)=h+vt-0.5at^2\\\\a=32ft/s[/tex]
To find the flight time you equal the height s to zero:
[tex]0=5ft+70\frac{ft}{s}\ t-0.5(32\frac{ft}{s^2})t^2\\\\0=5ft+70\frac{ft}{s}\ t-16\frac{ft}{s^2}t^2[/tex]
Then, you have a quadratic equation of the form:
[tex]ax^2+bx+c[/tex]
you use the quadratic formula in order to find the roots of the polynomial:
[tex]t_{1,2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\\\\a=-16\\\\b=70\\\\c=5\\\\t_{1,2}=\frac{-70\pm \sqrt{(70)^2-4(-16)(5)}}{2(-16)}\\\\t_{1,2}=\frac{-70\pm 72.24}{-32}\\\\t_1=4.44s\approx4s\\\\t_2=-007s[/tex]
you take the positive value of t because this has physical meaning.
Hence:
the time is C) 4 seconds
From the data provided, the time taken for the baseball to hit the ground is 4.0 seconds
What is the time taken for the baseball to hit the ground?The function: s(t) = vt + h – 0.5at^2 represents the height of an object
From the data provided:
v = 70 ft/sfinal height above ground, s = 0h = 5 fta = 32 ft/s^2t = ?Substituting the values:
0 = 70t + 5 - 0.5(32)t^2
16t^2 -+ 70t - 5 = 0
solving quadratically:
[tex]t = \frac{ - b \sqrt{b {}^{2} - 4ac} }{2a} [/tex]
[tex]t = \frac{ - 70 \sqrt{ {70}^{2} - 4 \times ( - 16) \times 5} }{2 \times ( - 16)} [/tex]
t = 4.4 s or - 0.07
taking only positive values for t, t= 4 seconds
Therefore, the time taken for the baseball to hit the ground is 4.0 seconds.
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Elabora una tabla, como la del ejemplo, con los resultados obtenidos en los test que desarrollaste en actividades anteriores. Luego, responde: ¿qué indican esos resultados con respecto a tu condición física y cómo se relacionan con tu salud? A partir de tus respuestas, plantéate el reto de mejorar tu condición física manteniendo o mejorando tu rutina de ejercicios o la práctica permanente de actividad física.
Explanation:
Clear rendering reads;
"Make a table, like the one in the example, with the results obtained in the tests you carried out in previous activities. Then answer: What do these results indicate regarding your physical condition and how do they relate to your health? From your answers, consider the challenge of improving your physical condition by maintaining or improving your exercise routine or permanent practice of physical activity".
So the incomplete text above it seems you've been instructed to perform an experiment and then state your result/analysis.
In what way are Earth and Mars similar?
A
They both have rings.
B
They are both outer planets.
C
They each have two moons.
D
They both have rocky surfaces.
Answer:
D they both have rocky surfaces
The earth and mars are similar to each other because both the planets have rocky surfaces. Thus, the correct option is D.
What are the Earth and mars?Earth and Mars are similar when it comes to their basic makeups, however it has been given that they are both the terrestrial type of planets. Earth and mars, both are differentiated between a dense metallic core and an overlying mantle and crust which are composed of less dense materials like silicate rocks.
Mars is about the half the size of the Earth by diameter and has a much thinner atmosphere, with an atmospheric volume which is less than 1% of the volume of the Earth. The atmospheric composition of the two planets are also significantly different because primarily they are carbon dioxide-based, while the Earth's is rich in nitrogen and oxygen gases.
Therefore, the correct option is D.
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Care din propozitiile de mai jos sunt propozitii simple si care sunt propozitii dezvoltate? Argumentati oral raspunsurile a) mâța a mâzgălit mâsuța. B) va găti bunica c) pisica toarce d) voi nu iubiți pisicile? E) dintr-o săritură, mâța va fi la geam f) noi nu ajungeam la timp niciodată
Answer:
a) developed
b) simple
c) simple
d) developed
e) developed
f) developed
Question:
Which of the following sentences are simple sentences and which are developed sentences? Orally argue the answers
a) the cat scribbled the little girl.
b) Grandma will cook
c) The cat will spin
d) You don't love cats?
e) in one jump, the cat will be at the window
f) we will never arrived on time
Explanation:
To differentiate the simple sentences from the developed sentences, let's understand what they are.
A Simple sentence is a sentence that contain a subject and a predicate. The sentence is complete in thought.
A developed sentence is a sentence that contain a subject, predicate as well as other parts of sentence.
a) the cat scribbled the little girl (developed)
b) Grandma will cook (simple)
c) The cat will spin (simple)
d) You don't love cats? (developed)
e) in one jump, the cat will be at the window (developed)
f) we will never arrived on time (developed)
Hence option b and c are simple sentences, while options a, d, e and f are developed.
The threshold frequency in a photoelectric experiment is most closely related to the A) brightness of the incident light B) work function of the photoemissive metal C) area of the photoemissive metal D) thickness of the photoemissive metal
The correct option is "work function of the photoemissive metal". The threshold frequency in a photoelectric effect experiment is most closely related to the work function of the photoemissive metal, which is the amount of energy required to eject an electron from the metal's surface.
The threshold frequency in a photoelectric experiment is closely related to the work function of the photoemissive metal (Option B). The threshold frequency is a characteristic of a metal and represents the minimum frequency of incident light required to eject electrons from the metal surface. If the frequency of the incident light is below this threshold, no photoelectrons are ejected regardless of the light's intensity or any other factors, such as the area or thickness of the metal.
In the case of using a metal with a lower threshold frequency (Option 3), this would correspond to a photoemissive metal with a lower work function, allowing electrons to be ejected with lower frequency (and thus, less energetic) light. Conversely, if a metal with a higher work function is used (Option 4), photons with energy less than this work function would not eject electrons, as their energy would be insufficient to overcome the electron binding energy inherent to the metal.
How is mechanical energy calculated?
A. by adding potential energy and kinetic energy
B. Oby subtracting potential energy from kinetic
energy
C. by multiplying potential energy and kinetic energy
D. by dividing potential energy by kinetic energy
Answer: [A] "by adding potential energy and kinetic energy"
Explanation: Mechanical Energy = Potential Energy + Kinetic Energy
Answer: d
Explanation:
g = 10 N/kg or 10 m/s2
A tennis ball of mass 0.2 kg drops from a height of 20 m. When it hits the ground, it bounces to a height of 14 m.
Describe what happens next
What was the Potential Energy (EP) of the ball before it fell?
What was the efficiency of the bounce?
How fast will Danielle be moving as she reaches the bottom of the hill?
Answer:
a) [tex]U_{g} = 40\,J[/tex], b) [tex]\eta = 70\,\%[/tex], c) [tex]v = 20\,\frac{m}{s}[/tex]
Explanation:
a) The initial potential energy is:
[tex]U_{g} = (0.2\,kg)\cdot \left(10\,\frac{m}{s^{2}} \right)\cdot (20\,m)[/tex]
[tex]U_{g} = 40\,J[/tex]
b) The efficiency of the bounce is:
[tex]\eta = \left(\frac{14\,m}{20\,m} \right)\times 100\,\%[/tex]
[tex]\eta = 70\,\%[/tex]
c) The final speed of Danielle right before reaching the bottom of the hill is determined from the Principle of Energy Conservation:
[tex]K = U_{g}[/tex]
[tex]U_{g} = \frac{1}{2}\cdot m \cdot v^{2}[/tex]
[tex]v = \sqrt{\frac{2\cdot U_{g}}{m} }[/tex]
[tex]v = \sqrt{\frac{2\cdot (40\,J)}{0.2\,kg} }[/tex]
[tex]v = 20\,\frac{m}{s}[/tex]