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A force acting on a 5 kg body increases its speed uniformly from 2.0 m/s to 8.0 m/s

through 5 seconds.
a) What is the initial and final momentum of the body?
b) What impulse did the body receive?

User Horstr
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1 Answer

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Answer:

We can use the formula for momentum to find the initial and final momentum of the body:

p = mv

where p is momentum, m is mass, and v is velocity.

Initial momentum:

p1 = mv1

p1 = 5 kg ( 2.0 m/s )

p1 = 10 kg m/s

Final momentum:

p2 = m(v2)

p2 = 5 kg ( 8.0 m/s )

p2 = 40 kg m/s

Therefore, the initial momentum of the body is 10 kg m/s and the final momentum is 40 kg m/s.

for b, we can use the formula for impulse to find the impulse received by the body:

J = F(t)

where J is impulse, F is force, and t is time.

To find the force, we can use Newton's second law of motion:

F = ma

The acceleration:

a = (v2 - v1) / t

a = (8.0 m/s - 2.0 m/s) / 5 s

a = 1.2 m/s^2

Now we can find the force acting on the body:

F = ma

F = 5 kg (1.2 m/s)^2

F = 6 N

Finally, we can find the impulse received by the body:

J = F(t)

J = 6 N5 s

J = 30 N s

Therefore, the body received an impulse of 30 N s

User Jmunsch
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