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3 years ago

12

You are going sledding with your little cousins during a well-earned break. You push your 23 kg cousin so that they have a speed

of 6 m/s at the top of the hill that is 17 m tall. What is the kinetic energy of your cousin at the top of the hill (after you push)? (in J)

2 answers:

pogonyaev3 years ago

7 0

Answer:

kinetic energy = 414 J

Explanation:

given data

mass = 23 kg

speed = 6 m/s

height = 17 m

to find out

kinetic energy

solution

we get kinetic energy that is express as

kinetic energy = 0.5 × m × v² ..........................1

here m is mass and v is speed so

put here value we get kinetic energy

kinetic energy = 0.5 × 23 × 6²

kinetic energy = 414 J

Thepotemich [5.8K]3 years ago

5 0

Answer:

414 J

Explanation:

mass, m = 23 kg

velocity, v = 6 m/s

Kinetic energy is given by

K = 0.5 mv²

K = 0.5 x 23 x 6 x 6

K = 414 J

Thus, the kinetic energy is 414 J.

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Answer:

The current would be same in both situation.

Explanation:

Given that,

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Using formula of induced emf is

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Using formula of current

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Now, if the number of turn is 22 , then induced emf would be

$\epsilon'=NA\dfrac{dB}{dt}$

Then the current would be

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Hence, The current would be same in both situation.

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Concept Simulation 20.4 provides background for this problem and gives you the opportunity to verify your answer graphically. Ho

77julia77 [94]

Answer:

The time constant is 1.049.

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Given that,

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zlopas [31]

Answer:

-22,150 N

Explanation:

When the youngster jumps off the platform, during the fall her initial potential energy is converted into kinetic energy, according to the law of conservation of energy. Therefore, we can write:

$mgh=\frac{1}{2}mu^2$

where the term on the left is the potential energy while the term on the right is the kinetic energy, and where

m = 50.0 kg is the mass of the youngster

$g=9.8 m/s^2$ is the acceleration due to gravity

h = 1.00 m is the heigth of the platform

u is the speed of the youngster as she reaches the floor

Solving for u,

$u=\sqrt{2gh}=\sqrt{2(9.8)(1.00)}=4.43 m/s$

Then, when the youngster hits the floor, the force exerted on her during the deceleration is given by:

$F=\frac{\Delta p}{\Delta t}=\frac{m(v-u)}{\Delta t}$

where $\Delta p$ is her change in momentum, and where

m is the mass

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u = 4.43 m/s is the initial velocity

$\Delta t=10.0 ms =0.010 s$ is the duration of the collision

Substituting,

$F=\frac{(50.0)(0-4.43)}{0.010}=-22150 N$

And the negative sign means the direction of the force is opposite to the motion (so, upward).

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