The answer is b. after is and ways. You always pause after a comma before moving on to the rest of the sentence.
Answer:
Explanation:
It's none of the above. The sentence is complete the way it stands. There is no need for any more punctuation.
So the answer is D.
A 20kg boy on a 5 kg skateboard coasts to a rest from a speed of 4.5m/s while traveling a distance of 20m on the sidewalk. Draw a free body diagram for this situation and calculate the acceleration of the skateboard, the force of friction on the skate board and the coefficient of friction between the skateboard and the sidewalk.
Answer:
a = -.51 m/s²
coefficient of friction = .05
fk= 12.25 N
Explanation:
mass = 20 + 5kg
weight = 25kg ·9.8 = 245 N
There are many ways to do this I am sure but I did this:
1. found a by using vf²=vi²-2aΔx. accel is - because it is slowing down.
started at 4.5 m/s, final = 0 and Δx=20....a=-.51 m/s²
2. the force acting on the object is the friction force which has to equal the mass(accel).
-fk (going to left on free body diagram) = ma
-mu·n = ma
-mu·245N = 25 (-.51)
mu=.05
fk= .05(245N) = 12.25 N
The kinematics and Newton's second law allow to find the results for the questions of the movement of the child and the skateboard are:
a) the deceleration is a = 0.51 m / s²
b) The friction force is: fr = 12.75 N
c) The friction coefficient is equal to: μ = 0.052
Given parameters
The child's mass M = 20 kg. The mass of the skateboard m = 5 kg. Initial velocity vo = 4.5 m / s. The distance traveled x = 20 m.To find
a) Acceleration.
b) The friction force.
c) The coefficient of friction.
a) Kinematics studies the movement of bodies, finding relationships between their position, speed and acceleration.
Since the child ends up at rest, his final velocity is zero (v = 0), let's use the relation.
v² = v₀² - 2 a x
0 = v₀² - 2ax
a = [tex]\frac{v_o^2}{2x}[/tex]
a = [tex]\frac{4.5^2 }{2 \ 20}[/tex]
a = 0.51 m / s²
b) Newton's second law states that the net force is proportional to the product of the mass and the acceleration of the body.
A free-body diagram in a diagram of the forces without the details of the body, in the attached we can see the free-body diagram of the system.
Let's write Newton's second law, since the boy and the scooter do not separate, we use the total mass.
y-axis
N-W = 0
N = W
N = (M + m) g
N = (20 +5) 9.8
N = 245 N
x-axis
fr = [tex]m_{total} \ a[/tex]
Fr = (20+ 5) 0.51
fr = 12.75 N
c) Friction force is a macroscopic force of the interactions between the two surfaces and has the formula.
fr = μ N
μ = [tex]\frac{fr}{N}[/tex]
μ = 12.75 / 245
μ = 0.052
In conclusion, using kinematics and Newton's second law we can find the results for the questions of the movement of the boy and the skateboard are:
a) The deceleration is a = 0.51 m / s²
b) The friction force is: fr = 12.75 N
c) The friction coefficient is equal to: μ = 0.052
Learn more here: https://brainly.com/question/5183024
What is the DNA in the G1 stage called?
Final answer:
The DNA in the G1 phase is unreplicated chromosomal DNA, as this phase involves the cell growing and accumulating the necessary components and energy for upcoming DNA replication in the S phase.
Explanation:
Understanding the G1 Phase of Interphase
The G1 phase is the initial stage of the cell cycle and falls under interphase. It is often referred to as the "first gap" mainly because there are no significant changes visible under a microscope during this period. Despite this, the cell is not dormant; it is engaged in vital preparatory activities. During the G1 stage, the cell grows and increases in size, meticulously assembling the basic biochemical compounds needed for DNA replication.
This includes the building blocks of chromosomal DNA and the associated proteins. In addition to this, the cell is also building up sufficient energy reserves necessary to go through the upcoming phase of DNA synthesis or the S phase, where each chromosome is replicated.
Which gas in Earth’s atmosphere forms ozone?
oxygen
nitrogen
water vapor
carbon dioxide
Which characteristics describe the troposphere? Check all that apply.
is the innermost layer
contains the ozone layer
has the highest air pressure
spans 12–50 km above Earth
is a good place for planes to fly
Which gas in Earth’s atmosphere has increased over time due to burning fossil fuels?
oxygen
nitrogen
water vapor
carbon dioxide
Which phrases describe air density? Check all that apply.
increases as altitude increases
equals mass divided by volume
pushes molecules in one direction
exerts more pressure as it increases
measures how tightly molecules are packed
Answer:
1) Oxygen 2) So The Troposphere is a good place for planes to fly. 3) [tex]CO_{2}[/tex] 4) It measures how tightly molecules are packed, It pushes molecules in one direction
Explanation:
1) Which gas in Earth’s atmosphere forms ozone?
Oxygen since Ozone is formed when [tex]O_{2} [/tex] receives Ultraviolet in its energetic form[tex] O_{3}[/tex], in a process called photolise.
2) Which characteristics describe the troposphere? Check all that apply.
This layer is the closest to the Earth although it is thicker in the Equator. Most planes fly in there.
So The Troposphere is a good place for planes to fly.
3) Which gas in Earth’s atmosphere has increased over time due to burning fossil fuels?
The outcome burning of fossil fuels is among other gases is the [tex]CO_{2}[/tex]
4) Which phrases describe air density?
Although these are not precise descriptions:
It measures how tightly molecules are packed The more density the more molecules are packed in given volume.
It pushes molecules in one direction, In a column of air the more the altitude the more molecules are pushed into the lower altitude region.
Which of following scientists helped lay the groundwork for the development of the concept of gravity by claiming the the sun, not earth, was at the center of the universe
Nicolaus Copernicus
Nicolaus Copernicus is the scientist who put forward a model which placed sun instead earth as the center of the universe
What is the SI unit for momentum
The impulse of the material point is equal to the product of mass and its velocity.
The unit of measurement of the imouls is:
[P] = [m] * [v] = kg * m / s.
Answer:
kg·m/s
Explanation:
The momentum of a body is calculated according to the following formula.
momentum = mass * velocity
Since the SI unit unit for mass is kilogram and the SI unit for velocity is metres/second then the multiplication of both will, algebraically give kg·m/s
imagine you are in a sports team, there is one player on you team who is the star athlete. you notice that he/she does not include players who are good as they are; he/she puts down their teammates. how would you encourage this player to be more inclusive and supportive of all the player on the team? create a dialogue with this person.
Final answer:
In order to encourage the star athlete to be more inclusive and supportive, start by acknowledging their talent and having a gentle conversation about their behavior. Emphasize the importance of teamwork and suggest activities to foster inclusivity.
Explanation:
To encourage the star athlete on your sports team to be more inclusive and supportive of all the players, you could have a dialogue with them. Start by acknowledging their talent and achievements and express your admiration for their skills. Then, gently bring up the issue of their behavior towards other players and explain how it affects team dynamics.
Next, emphasize the importance of teamwork and how their support can uplift and motivate other players. Share examples of successful teams that have thrived because of a positive and inclusive team culture. Encourage them to recognize and appreciate the strengths of their teammates.
Suggest activities or team-building exercises that can help foster inclusivity and encourage interactions among all team members. Additionally, remind them of the power of their influence as a star athlete and how they can set an example for others by embracing a supportive and inclusive attitude.
a bowling boal has a mass of 5 kg. what happens to its momentum when its speed increase from 1 m/s to 2 m/s?
Answer:
change in momentum (p) = m. (v₂ -v1)
= 5. (2-1)
momentum = 5 m/s.
Answer:
Momentum also increases (doubles from 5 kgm/s to 10 kgm/s)
Explanation:
the momentum is given by
[tex]p=mv[/tex]
where [tex]p[/tex] is momentum, [tex]m[/tex] is mass of thebowling ball ([tex]m=5kg[/tex]), and [tex]v[/tex] is speed.
The momentum when [tex]v=1m/s[/tex] is:
[tex]p=(5kg)(1m/s)\\p=5kgm/s[/tex]
and the momentum when [tex]v=2m/s[/tex] is:
[tex]p=(5kg)(2m/s)\\p=10kgm/s[/tex]
so we can see that the momentum doubles from 5 kgm/s to 10 kgm/s.
how much work does a 30W engine do if it operates for 40 seconds
Given that :
Power (P) = 30 W ,
time (t) = 40 s,
Work = ?
we know that, power is defined as rate of doing work
Power = Work ÷ time
=> Work = Power × time
= 30 × 40
W = 1200 J
What is used to identify elements on the periodic table?
Elements on the periodic table are identified by their atomic number (Z), which indicates the number of protons in an atom's nucleus, and by their unique chemical symbol that may derive from their English or Latin names.
Identifying Elements on the Periodic Table
The periodic table is a tabular arrangement of chemical elements, organized by their atomic number, electron configurations, and recurring chemical properties. Each element on the periodic table is represented by a unique chemical symbol, which is a one-, two-, or three-letter abbreviation of its name. The atomic number, represented by the symbol Z, defines the identity of an element by indicating the number of protons in the nucleus of an atom of that element.
For each element listed in the periodic table, you can find its atomic number above the chemical symbol. This is central to the element's identity, as no two different elements share the same number of protons. Additionally, the element's atomic mass is included in the entry, giving an indication of the relative mass of an atom of that element compared to other elements.
Historical elements with symbols based on their Latin names, such as Fe for iron (ferrum) and Pb for lead (plumbum), may seem unrelated to their English names. The periodic table also helps in identifying elements as metals, nonmetals, and organizes them into groups and periods where elements exhibit similar properties.
A pendulum makes 36 vibrations in 60 seconds, what is its: Period? And Frequency
Answer:
Period = 1.67 seconds
Frequency = 0.6 Hz
Explanation:
Number of vibrations in 60 seconds = 36
Frequency is defined as vibrations per second.
So, Frequency = 36/60 = 0.6 Hz
Time period is defines as time taken for 1 vibration,
So, Time period = 60/36 = 1.67 seconds.
The period of vibration of a simple pendulum is 1.67 s.
The frequency of vibration of a simple pendulum is 0.6 Hz.
What is frequency of vibration?The frequency of vibration of a simple pendulum is the number of complete oscillation of the pendulum per second.
F = n/t
where;
n is number of vibrationst is time of vibrationF = 36/60
F = 0.6 Hz
What is period of vibration?The period of vibration is the inverse of frequency of vibration.
T = 1/f
T = 1/0.6
T = 1.67 s
Learn more about period and frequency here: https://brainly.com/question/301048
The planet Jupiter’s mean orbital radius is 5.2025 AU’s. what is the period of Jupiter in earth years?
11.86 years, or around that time it would take about 12 years.
The period of Jupiter's orbit around the sun is 11.862 Earth years.
What is Kepler's law of planetary motion?Kepler's laws of planetary motion are a set of three laws that describe the motion of planets around the sun. They were formulated by the German mathematician and astronomer Johannes Kepler in the early 17th century, based on observations made by the astronomer Tycho Brahe.
Kepler's first law, also known as the law of orbits, states that the planets move in elliptical orbits around the sun, with the sun located at one of the foci of the ellipse.
Kepler's second law, also known as the law of areas, states that the line connecting a planet to the sun sweeps out equal areas in equal times. This means that a planet moves faster when it is closer to the sun and slower when it is farther away.
Kepler's third law, also known as the law of harmonies, relates the period and distance of a planet's orbit to its mass and the mass of the sun. Specifically, it states that the square of a planet's orbital period is proportional to the cube of its average distance from the sun.
These laws helped to revolutionize the field of astronomy and laid the foundation for the later development of Isaac Newton's laws of motion and gravitation.
Here in the question,
We can use Kepler's third law of planetary motion to calculate the period of Jupiter's orbit around the sun, which relates the period of an orbit to the average distance of the planet from the sun.
Kepler's third law states that:
(T^2) / (R^3) = (4π^2) / G,
where T is the period of the orbit, R is the average distance between the planet and the sun, G is the gravitational constant, and π is pi.
To solve for T in Earth years, we need to convert Jupiter's average distance from AU to kilometers (km) and then to meters (m), and we need to convert Earth years to seconds.
1 AU = 149,597,870.7 km
1 year = 365.25 days = 31,557,600 seconds (approx.)
So, Jupiter's average distance from the sun is:
R = 5.2025 x 149,597,870.7 km = 778,547,200 km = 7.785 x 10^11 m
Substituting the values into Kepler's third law, we get:
(T^2) / (7.785 x 10^11 m)^3 = (4π^2) / 6.6743 x 10^-11 m^3/(kg s^2)
Solving for T, we get:
T = ∛[(7.785 x 10^11 m)^3 / ((4π^2) / 6.6743 x 10^-11 m^3/(kg s^2))] = 11.862 Earth years
Therefore, the period of Jupiter's orbit around the sun is approximately 11.862 Earth years.
To learn more about Newton's law of motion click:
brainly.com/question/29775827
#SPJ2
From a window that is 20 m from the ground a stone with a speed of 10m / s is thrown vertically upwards. Calculate:
a) the maximum height reached and the time it takes to reach it
b) the total time that is in the air
a)
consider the motion in upward direction as positive and down direction as negative
Y₀ = initial position of the stone = 20 m
v₀ = initial velocity of the stone = 10 m/s
a = acceleration = - 9.8 m/s²
Y = final position of the stone when it reach the maximum height
v = final velocity at the maximum height = 0 m/s
t = time taken to reach the maximum height
Using the equation
v² = v₀² + 2 a (Y - Y₀)
0² = 10² + 2 (- 9.8) (Y - 20)
Y = 25.1 m
also using the equation
v = v₀ + a t
inserting the values
0 = 10 + (- 9.8) t
t = 1.02 sec
b)
consider the motion in upward direction as positive and down direction as negative
Y₀ = initial position of the stone = 20 m
v₀ = initial velocity of the stone = 10 m/s
a = acceleration = - 9.8 m/s²
Y = final position of the stone when it reach the ground = 0 m
t = time taken to reach the ground
Using the equation
Y = Y₀ + v₀ t + (0.5) a t²
0 = 20 + 10 t + (0.5) (- 9.8) t²
t = 3.3 sec
how far will a rubber ball fall on 20 seconds?
Given that:
time (t) = 20 s ,
S = ?
We know that S = ut + 1/2 at² meters
since free fall, a = g = 9.81 m/s² ; u =0 ;
S = 0 + 1/2 × 9.81 × 20²
S= 1962 m
A 0.5-kg ball moving at 5 m/s strikes a wall and rebounds in the opposite direction with a speed of 2 m/s. If the impulse occurs for a time duration of 0.01 s, then the average force (magnitude only) acting upon the ball is ____ Newtons.
Given that:
mass of the ball (m) = 0.5 Kg ,
ball strikes the wall (v₁) = 5 m/s ,
rebounds in opposite direction (v₂) = 2 m/s,
time duration (t) = 0.01 s,
Determine the force (F) = ?
We know that from Newton's II law,
F = m. a Newtons
(velocity acting in opposite direction, so a = ( (v₁ + v₂)/t
= m × (v₁ + v₂)/t
= 0.5 × (5 + 2)/0.01
= 350 N
The force acting up on the ball is 350 N
how do we measure or think of speed in the united states?
I'm not sure what you mean by "think of speed", but the way we measure it is by plugging the numbers into this formula: distance divided by time. If you are trying to find an average speed, then your formula would be: total distance divided by total time. I hope this helped!:)
Please find the equivalent resistance. (the question has been attached below)
Answer:
The final (equivalent) resistance of the circuit is 5 Ohms.
Explanation:
Use the formulas for combining two resistors
(a) in series [tex]R=R_1+R_2[/tex]
(b) in parallel [tex]\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}[/tex]
Steps:
Start simplifying the circuit at the right end (I am indexing the resistors by the index of the current in the schema)
Step 1: combine resistors 5 and 6 (parallel):
R_A = 1/(1/10+1/30)= 30/4 =15/2 Ohm
Step 2: combine 4 and 7 with R_A (series)
R_B = R4+R_A+R7 = 2 + 15/2 + 1/2 = 10 Ohm
Step 3: Resistor 3 with R_B (parallel):
R_C = 1/(1/15 + 1/10) = 6 Ohm
Step 4: Resistor 2 with R_C (parallel):
R_D = 1/(1/12+1/6) = 4 Ohm
Ste 5 Resistor 1 with R_D (series):
R = 1 + 4 = 5 Ohm
The final (equivalent) resistance of the circuit is 5 Ohms.
which of the following is an inclined plane wrapped around a rod?
A. A Screw
B. A Lever
C. A Wheel and Axle
D. A Pulley
Alright well the Answer to your question is A). Screw
Hope this helps have a nice day : )
If u want i can explain why
Answer:
answer is screw my good fellow
Explanation:
Please help, I really don't know
Estimate the length of the day if the centripetal acceleration at the equator due to the spinning Earth was equal to the acceleration of free fall (g=9.8 ms⁻²)
Thanks
By setting the formula for centripetal acceleration equal to the acceleration due to gravity and using the known radius of the Earth, we find the speed at the equator. Using this speed to divide the Earth's equator's circumference, we estimate the length of a day to be approximately 1.41 hours or 84 minutes.
Explanation:To estimate the length of the day if the centripetal acceleration at the equator due to the spinning Earth was equal to the acceleration of free fall (g=9.8 ms⁻²), we need to utilize known physical constants and the formula for centripetal acceleration.
The formula for centripetal acceleration is a_c = v²/r, where v is the speed, and r is the radius of the circular path. We set this equal to g (9.8 m/s²), so v²/r = 9.8 m/s2. Given the known radius of Earth R = 6.376 x 10^6 m, we can solve for the speed at the equator v.
From the speed, we can calculate the time it would take for the Earth to complete a single rotation. Since the distance the Earth covers in a day is a circular path around the Earth’s equator, this distance is equal to the Earth's circumference, which is 2πR. Dividing this by the speed gives the length of a day, which we can calculate to be 1.41 hours or approximately 84 minutes.
Learn more about Centripetal Acceleration here:https://brainly.com/question/34218083
#SPJ2
Why are electric motors used in circuits?
An electric motor converts electrical energy into physical movement. Electric motors generate magnetic fields with electric current through a coil. The magnetic field then causes a force with a magnet that causes movement or spinning that runs the motor. Electric motors are used in all sorts of applications.
Why will interference occur
Two waves interfere when they run into each other.
The barrier reflects waves that run straight into it. It acts as a wave source and sends wave pulses back up the page towards the incoming waves.
Imagine a loose string tied to a wall. Someone sends two consecutive pulses along the string towards the wall. The first pulse gets reflected right away. It will travel backward towards the person holding the string. Along its way, it will run into the second pulse. The two pulses will interfere. The wall will make the reflected pulse out of phase with the second one. They will end up creating a destructive interference.
So is the case with the water waves running into the barrier. The barrier will send incoming waves back toward where they came from. Reflected waves interfere with incoming ones.
An object with a mass of 70 kilograms is supported at a height of 8 meters above the ground, what's the potential energy of the object with respect to the ground?
Answer:
5488 Joules
Explanation:
Use the formula for the potential energy:
[tex]E_p = mgh = 70kg\cdot 9.8\frac{m}{s^2}\cdot 8m = 5488 J[/tex]
On a hike, you travel 2800 m in 2 h. What is your average speed?
Firstly, to find speed you need to remember the speed formula:
Speed = Distance ÷ Time
You can do it by doing 2800 ÷ 2 but that gives m/h (metres per hour)
So to convert hours into seconds, you multiply 2 by 7200 (amount of second in 2 hours:
2 * 7200 = 14400 seconds
Now we can do distance ÷ time by plugging the values in:
2800 ÷ 14400 = [tex]\frac{7}{36}[/tex] ≈0.194
So the average speed is 0.194m/s (metres per second) Hope this helps!CAN SOMEONE PLEASE HELP ME WITH MY PHYSICS QUESTIONS? I NEED CORRECT ANSWERS ONLY!
Free fall is a situation in which the only force acting upon an object is gravity. Why do all objects in free fall have the same acceleration?
A) their masses are always the same
B) acceleration due to gravity is always the same
C) the distance between two objects is always the same
D) the gravitational force between two objects are always the same
According to the experiments done and currently verified, in vacuum (this means there is not air or any fluid), all objects in free fall experience the same acceleration, which is the acceleration of gravity.
Now, in this case we are on Earth, so the gravity value is [tex]9.8\frac{m}{s^{2}}[/tex]
Note the objects experience the acceleration of gravity regardless of their mass.
Nevertheless, on Earth we have air, hence air resistance, so the afirmation "Free fall is a situation in which the only force acting upon an object is gravity" is not completely true on Earth, unless the following condition is fulfiled:
If the air resistance is too small that we can approximate it to zero in the calculations, then in free fall the objects will accelerate downwards at [tex]9.8\frac{m}{s^{2}}[/tex] and hit the ground at approximately the same time.
Which of the following shows a car holding a steady speed
The answer is the velocity that is in a straight horizontal line.
The second one as the velocity doesn't change over time.
Which waves can travel through a vacuum? A) light waves Eliminate B) ocean waves C) sound waves D) mechanical waves
A.) Light waves can travel through a vacuum.
The answer is A, light waves eliminate
How do climate factors affect temperature patterns where you live?
A primary succession does not include any invasive species
True or false
A primary succession does not include any invasive species. This is true statement.
What is primary succession?When a new piece of land is produced or is first exposed, primary succession occurs. This may occur, for instance, when lava solidifies and forms new rocks or when a glacier recedes and reveals bare rocks. In the initial succession, organisms have to start over. First, lichens may cling to rocks, followed by a few small plants capable of surviving without much soil. The term "pioneer species" refers to these.
More and larger plants start to colonize the region as a result of the decomposition of those plants, which gradually helps to create soil. Once sufficient soil has accumulated and sufficient nutrients are accessible, a climax community, such as a forest, is created. In the event that the site is disturbed after this, secondary succession takes place.
Learn more about primary succession here:
https://brainly.com/question/26675203
#SPJ5
Students can take the aspire test in ninth and grade
A. First
B. Tenth
C. Eleventh
D. Twelfth
Answer:
The correct answer is option B, tenth
Explanation:
ASPIRE test is basically given by students of ninth and tenth grade as pre-test to the ACT test. ACT ASPIRE test can be given from third grade till tenth grade. The scoring obtained in this test helps the student, teachers and parents to monitor the preparation of their kids towards completing a successful ACT test.
Apart from ninth and tenth grade , students belonging to lower grades (i.e from 3rd grade to 8th grade) can opt for online test. However, higher grades can opt for both online and paper based test.
Students can take the Aspire test in the ninth and grade Tenth. The correct option is B.
What is the Aspire test?The Aspire test is an assessment designed to measure students' readiness for college and careers. It evaluates their skills in English, math, reading, and science. The test is administered by the ACT organization and is typically taken by students in grades 3-10.
While students in ninth grade may be eligible to take the Aspire test, it is not the earliest grade at which it can be taken, and thus option A. First is not correct. The Aspire test is not typically administered to students in the first grade.
Option C. Eleventh and option D. Twelfth are not correct because by these grades, students may have already taken the ACT or SAT, which are the college entrance exams typically taken during the junior and senior years of high school.
Therefore, the correct option is B. Tenth, as this is the grade level at which most students take the Aspire test.
To learn more about SAT click:
https://brainly.com/question/30694582
#SPJ5
In which situation is maximum work considered to be done by a force
Answer:
Work done is maximum when the movement of object is in line and direction of force.OR
Work done is maximum, when displacement takes place along the direction of force. Work done is given by the equationW = F.S
W = F. S cos Θ
When cos Θ = 0° ; cos 0 = 1
Answer:
The angle between the force and displacement is 0°.
Explanation:
BRAINLIEST AND MAY DOUBLE POINTS!!!
how much power would a light bulb have if it used 30 joules of energy every 3 seconds
Given that:
Energy of bulb (Work ) = 30 J,
Time (t) = 3 sec
The power consumption = ?
We know that, Power can be defined as rate of doing work
Power (P) = Work(Energy supplied) ÷ time
= 30 ÷ 3
= 10 Watts
The power consumption is 10 W.