Momentum Physics│Please Help!

Question

1.A 5 kg object is moving with a velocity of 10 m/s. An impulse of 100 N/s is applied to the object. What is the momentum of the object after the impulse is applied?

2.A 4 kg mass moves at 2 m/s toward an 8 kg mass at rest. After the two objects collide the 4 kg mass is at rest. Assuming this is a closed system, what is the velocity of the 8 kg mass?

Answer 1

1.A 5 kg object is moving with a velocity of 10 m/s. An impulse of 100 N⋅s is applied to the object. What is the momentum of the object after the impulse is applied?

A 5 kg object is moving with a velocity of 10 m/s has momentum of mv = (5)(10) = 50 kg⋅m/s

I think that an applied impulse of 100 N⋅s (if its applied in the same direction as velocity) will increase the momentum of the object to 50 + 100 = 150 kg⋅m/s.

Answer

After the impulse is applied the momentum of the object is 150 kg⋅m/s

2.A 4 kg mass moves at 2 m/s toward an 8 kg mass at rest. After the two objects collide the 4 kg mass is at rest. Assuming this is a closed system, what is the velocity of the 8 kg mass?

Initial momentum = m₁v₁ = (4 kg)(2 m/s) = 8 kg⋅m/s

Momentum is conserved, so Final momentum = Initial momentum:

Final momentum = m₂v₂ = (8 kg)(v₂ m/s) = 8 kg⋅m/s

Solving for v_{2 gives}

v₂ = (8 kg⋅m/s)/(8 kg) = 1 m/s

Answer

The velocity of the 8 kg mass is 1 m/s