Starting initially at rest at t=0, a subway car accelerates to 29 m/s over a period of 6 seconds, and then begins to brake. Forty-eight (total) seconds after starting, it is moving at 12 m/s . What is its average acceleration in this 48-s interval?
Explain how the energy of a marble is transformed as it rolls down a ramp. Give evidence that energy of the marble remains the same at all points on the ramp.
Answer:
All the energy remains same actually.
Explanation: First, when it is dropped, it collects speed and kinetic energy, and also creates few amounts of sound and little thermal energy. For, example, you dropped the marble, and it rolled and bounced off towards the ramp. Take, it had 100 joules ( joule is the unit of energy, founded by scientist James Prescott Joule ). As it dropped, it created sound energy ( the clink sound ) and assume it had taken 50 joules. The rest are transformed to thermal and kinetic energy, assuming both energies took 25 joules. As it rolls down, it gains speed, gradually, and soon, it comes to halt in the ground by friction. Friction gives enough evidence as well as use of joules by sound, thermal and kinetic energies.
The x-coordinates of two objects moving along the x-axis are given as a function of time (t). x1= (4m/s)t x2= -(161m) + (48m/s)t - (4 m/s^2)t^2 Calculate the magnitude of the distance of closest approach of the two objects. x1 and x2 never have the same value.
To calculate the magnitude of the distance of closest approach of the two objects, we need to find the minimum distance between the x1 and x2 functions. The minimum distance occurs when the derivative of the difference between x1 and x2 is zero. We can find this point by equating the derivatives of x1 and x2 and solving for t.
Explanation:To calculate the magnitude of the distance of closest approach of the two objects, we need to find the minimum distance between the x1 and x2 functions. The minimum distance occurs when the derivative of the difference between x1 and x2 is zero. We can find this point by equating the derivatives of x1 and x2 and solving for t. Once we have the value of t, we can substitute it back into either x1 or x2 to find the minimum distance.
Take the derivative of x1 with respect to t: x1'(t) = 4 m/sTake the derivative of x2 with respect to t: x2'(t) = 48 m/s - 8 m/s^2 * tSet x1'(t) = x2'(t) and solve for t: 4 m/s = 48 m/s - 8 m/s^2 * tSolve the equation: t = 5 sSubstitute t=5s into x1 or x2 to find the minimum distance: x1(5s) = 20 mTherefore, the magnitude of the distance of closest approach of the two objects is 20 meters.
Exactly 3.0s after a projectile is fired into the air from the ground, it is observed to have a velocity v = (8.4 i^ + 4.9 j^)m/s, where the x axis is horizontal and the y axis is positive upward. Determine the horizontal range of the projectile. Determine its maximum height above the ground. Determine the speed of motion just before the projectile strikes the ground. Determine the angle of motion just before the projectile strikes the ground.
The problem requires understanding of projectile motion in Physics. One calculates multiple parameters of projectile's path by understanding vertical and horizontal motions independently. The given information can be used to calculate the horizontal range, maximum height, and angle of motion.
Explanation:The subject of this question involves understanding projectile motion. In physics, projectile motion is the motion of an object that is subject only to the acceleration of gravity. It involves two independent one-dimensional motions, one along the vertical axis and one along the horizontal axis.
To solve this problem, we observe the given initial vertical and horizontal velocities after a time 3.0s. Using the equations of motion, we can calculate different parameters asked in the question. The horizontal range of the projectile can be calculated by multiplying the horizontal velocity by the total time the projectile is in the air. The maximum height, speed of motion and the angle of motion just before the projectile strikes the ground can also be calculated using these principles.
Remember, the x and y motions in a projectile are independent, so we must handle them separately. The vertical motion will determine the total time spent in the air, and it will reach zero velocity at its highest point. The horizontal motion, under the absence of air resistance, remains constant.
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The horizontal range of the projectile is 25.2 m. The maximum height above the ground is 7.35 m. The speed of motion just before the projectile strikes the ground is 9.7 m/s. The angle of motion just before the projectile strikes the ground is 29.3 degrees.
Explanation:Using the given information, we can calculate the horizontal range, maximum height, speed of motion just before the projectile strikes the ground, and the angle of motion just before the projectile strikes the ground.
To determine the horizontal range, we need to find the time it takes for the projectile to reach the ground. Since the projectile is observed to have a velocity of (8.4 i^ + 4.9 j^) m/s after 3.0 seconds, we can assume that the time of flight is 3.0 seconds. The horizontal range is then given by multiplying the horizontal component of the velocity by the time of flight, which is R = vx * t = 8.4 m/s * 3.0 s = 25.2 m.
To determine the maximum height, we need to find the time it takes for the projectile to reach its peak. Since the projectile is at ground level initially and at its peak after 3.0 seconds, the time it takes to reach the peak is half of the total time of flight, which is t/2 = 3.0 s / 2 = 1.5 s. The maximum height above the ground is then given by multiplying the vertical component of the velocity at the peak by the time it takes to reach the peak, which is H = vy * t/2 = 4.9 m/s * 1.5 s = 7.35 m.
To determine the speed of motion just before the projectile strikes the ground, we can use the Pythagorean theorem to find the magnitude of the velocity vector. The speed of motion is given by the magnitude of the velocity vector, which is v = sqrt(vx^2 + vy^2) = sqrt((8.4 m/s)^2 + (4.9 m/s)^2) = 9.7 m/s.
To determine the angle of motion just before the projectile strikes the ground, we can use the inverse tangent function to find the angle. The angle of motion is given by the inverse tangent of the vertical component of the velocity divided by the horizontal component of the velocity, which is angle = tan^(-1)(vy / vx) = tan^(-1)(4.9 m/s / 8.4 m/s) = 29.3 degrees.
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Adding energy or increasing the speed of the particles at very low pressure in a solid would cause
A) boiling.
B) condensation.
C) melting.
D) sublimation.
How can density be used to help identify a substance?
Final answer:
Density is a physical characteristic of matter that can be used to identify substances. By comparing the density of an unknown substance to known density values, you can make reasonable guesses about its identity. Additional information may be needed to identify substances in objects composed of more than one material.
Explanation:
Density is a physical characteristic of matter that can be used to identify substances. Each substance has a characteristic density that can be used as a hint in identifying it. For example, gold has a density that is about 2.5 times the density of iron, which is about 2.5 times the density of aluminum. By comparing the density of an unknown substance to known density values, you can make reasonable guesses about the identity of the substance.
In some cases, additional information may be needed to identify the substances in an object composed of more than one material. For example, if a mixture has different materials with similar densities, it may be necessary to perform additional tests, such as chemical reactions or spectroscopy, to determine the exact composition of the mixture.
what is the total displacement of the car after five h?
0km
15km
20km
40km
The total displacement of the car after five hours - 0km.
Displacement -
Displacement is a vector quantity that refers to the object's overall change in position.change in final position from its initial positioncalculating the distance between an object's initial position and its final position.In physics terms, displacement is referred to as the variable s. The official displacement formula is as follows:s = sf – si.
where, s = displacement.
In the given graph there is a change in distance covered with the time that are:
after two hours it reaches 15 km away from the initial pointafter 4 hours car reaches 20 km away from the initial pointAfter 5 hours it returns back to the initial point.Thus, the displacement would be 0 km as the final point and initial point are the same.
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A airplane travels 3260 kilometers in 4 hours. What is the airplane average speed?
The elements helium, neon, and xenon are all part of the same _____ on the periodic table.
A. Diagonal
B. Period
C. Row
D. Group
the answer is D.group
hope this helps
D. Group
Explanation:
Helium, Neon and Xenon are all located under the same column in the periodic table. Elements within the same column in the periodic table are said to be in the same group, because they share similar chemical property: this is due to the fact that they have the same number of valence electrons (number of electrons in the outest shell).
Helium, neon and xenon are said to be part of the 'noble gas group'. The main property of these elements is that they do not react with other elements, because they have the outest energy shell completely filled with electrons, so they do not give/accept electrons to other atoms to form chemical bonds.
Can you help me with number 4 plz
How is sound detected by the brain? A.electromagnetic waves
B. Bones amplifying sound
C. Vibrations
D. Electrical impulses from the ear
Which value is equivalent to 178 centimeters?
1.78 millimeters
17.8 millimeters
1.78 meters
1.78 × 10-2 micrometers
1.78 × 10-5 kilometers
Answer:
1 centimetres = 10 millimetres
178 centimetres = 10 × 178 = 1780 millimetres
1 meters = 100 centimeters
178 centimeters = 178 ÷ 100 = 1.78 meters Plato answer
1 cm = 10 mm
1 mm = 1000 micrometers
1 cm = 10000 micrometers
178 cm = 178 × 10⁴ micrometers
1 kilometre = 1000 metres
1 metre = 100 cm178 cm = 178 ÷ 100 = 1.78 metres
1.78 metres = 1.78÷1000 = 1.78 × 10⁻³ kilometres
Explanation:
3. After studying about recycling, members of John’s biology class investigated the effects of various recycled products on plant growth. John’s lab group compared the effect of different aged grass compost on bean plants. Because decomposition is necessary for the release of nutrients, the group hypothesized that older grass compost would produce taller bean plants. Three flats of bean plants (25 per flat) were grown for 5 days. The plants were then fertilized as follows: flat A = 450. g of 3 month old compost; flat B = 450. g of 6 month old compost; flat C = 0 g of compost. The plants received the same amount of sunlight and water each day. At the end of 30 days, the group recorded the height of the plants in cm.
Hypothesis:
Independent Variable:
Dependent Variable:
Constant (at least one):
Control:
Number of groups:
Number of trials per group:
True or False? Facts and Figures are examples of variables? If it's false explain how you can fix it.
what creates an electric force field that moves electrons through a circuit ?
a. energy source
b. load
c. metal wires
d. resistance
Answer:
a. energy source
Explanation:
In a circuit, there is cell or battery. This is the energy source. The battery creates an electric force field which causes electrons to move through the circuit. The current moves from positive terminal to negative terminal of the battery.
Resistance opposes the current in the circuit. load is same as resistance. Metal wires are used to connect different components of a circuit.
Answer:
A is the correct answer!!
Explanation:
Have a great day :^)
what are two pieces of information that the sunscreen manufacturer might include on the label to help you decide if thhe sunscreen will be effective
Aluminum is used to make airplanes. Cast iron is used to make weight lifting equipment. Explain why the densities of these metals make them useful for these purposes?
Aluminum is light, tough, and corrosion-resistant, making it ideal for aircraft construction. In contrast, the high density and rigidity of cast iron make it suitable for the manufacture of weight-lifting equipment. The densities of these metals heavily influence their applications.
Explanation:The densities of both aluminum and cast iron play crucial roles in their respective applications. Aluminum, used in airplane construction, is known for its lightness, toughness, and resistance to corrosion which reduces the overall weight of the aircraft while maintaining structural integrity, an important factor in aerospace design.
On the other hand, cast iron, used in the manufacture of weight lifting equipment, has a much higher density than aluminum. This makes it ideal for producing heavy, sturdy equipment that is resistant to deformation, even under significant stress. Cast iron's high rigidity allows it to handle the force exerted during weightlifting.
Overall, it's the properties derived from these metals' densities that make them suitable for their distinct applications - the lightness of aluminum for flight efficiency in aviation and the weights possible from high-density cast iron in fitness.
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NEED HELP ASAP IF I FAIL THIS ONE I GET A F
If you want to cause an object to move, what should you do?
a Apply balanced forces.
b Apply neutral forces.
c Apply potential forces.
d Apply unbalanced forces.
What profession is most likely to make use of amphoras and candelas
Final answer:
The profession most likely to make use of amphoras and candelas is an archaeologist or historian.
Explanation:
The profession most likely to make use of amphoras and candelas is an archaeologist or historian.
Amphoras were large vessels used for shipping liquid goods in the Mediterranean world. They were essential for trade, transportation, and storage. Historians study past civilizations, including their economies and trade networks, and archaeologists excavate ancient sites, including tombs and graves, where they may find artifacts like amphoras.
Candelas, on the other hand, are units of luminous intensity used in lighting design and engineering. This profession may involve designing and using light fixtures, such as candelabras, which are candle holders that can provide both functional and aesthetic lighting.
Scientific models A. help to predict future events B. Prove that an object exists C.determine the distance to far off stars D. Show that the scientific method works
As a wave travels through a medium, it displaces particles in a direction parallel to the motion of the wave. We can conclude this is a
Answer:longitudinal wave
Explanation:. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves.
Which of the following has mechanical energy? Car battery Compressed spring Glowing incandescent lightbulb Nucleus of uranium atom
Answer:
the correct answer is the lightbulb
Explanation:
i took the assighnment and got it correct
How many places are there for electrons in the second shell of an atom?
Answer:
Eight electrons.Explanation:
An atom is composed by shells, each shell can contain a limited number of electrons. The first one can contain two electrons. The second shell contains up to eight electrons. The third shell contains up to 18.
There's a formula to calculate the number of electrons:
[tex]2(n^{2} )[/tex]
What important attitudes do successful scientists possess?
Curiousity. - A scientist shows interest and pays particular attentions to objects or events.
Honesty. - A scientist gives a truthful report of observations.
Open-Mindedness. - A scientist listens to and respects the ideas of others
8. How does inertia act on an object that is moving in a circle? A. It causes the object to speed up as it moves. B. It causes the object to move along a straight path. C. It directs the object toward the center of the curve.
Answer: its D
Explanation:
took on study island
Our understanding of the Atom has changed over time. which idea that was once accepted is now considered scientifically inaccurate
Answer:
Explained
Explanation:
From Rutherford's alpha ray scattering experiment, we know that most of the spaces in an atom is empty. It is so because most of the alpha particles in that scattering experiment had gone Undeviated without any deflection from the positively charged nucleus.
Hence, atom can not be considered as a compact solid sphere, which was once considered by the J.J. Thomson.
The relationship between the mass m of a material, its volume V, and its density D is
A. V= mD
B. Vm=D
C. DV=m
D. D+V=m
The relationship between the mass m of a material, its volume V, and its density D is DV = m
What is volume ?
Volume is a three dimensional space occupy by the body of particular shape. Generally expressed in cubic meter.
So, let V be the volume of body in cubic centimeters and
the mass of body is m than Density D of diamond is calculated as :
[tex]\begin{aligned}D&=\frac{m}{V}\\DV&=m \end{aligned}[/tex]
Therefore,The relationship between the mass m of a material, its volume V, and its density D is DV = m
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What is one positive ecological impact of switching to biological farming?
What is the value of -2 + 100 - (-50)?
A truck with 0.420 m radius tires travels at 32 m/s. What is the angular velocity of the rotating tires in radians per second? What is the angular velocity of the rotating tires in rev/min?
Answer : [tex]\omega=76.19\ radians/second[/tex] and [tex]\omega=727.55\ rev/min[/tex]
Explanation :
It is given that,
The radius of the truck, r = 0.420 m
Velocity of the truck, v = 32 m/s
We have to find the angular velocity of the rotating tires.
The relation between the angular velocity and the linear velocity is :
[tex]v=r\omega[/tex]
[tex]\omega[/tex] is the angular velocity
[tex]\omega=\dfrac{v}{r}[/tex]
[tex]\omega=\dfrac{32\ m/s}{0.420\ m}[/tex]
[tex]\omega=76.19\ radians/second[/tex]
We know that, 1 revolution = 2π radian
So, [tex]\omega=727.55\ rev/min[/tex]
Hence, this is the required solution.