A 9 kg lead brick falls from a height of 1.8 m. a) Find the momentum as it reaches the ground. b) What impulse is needed to bring the brick to rest? c) The brick falls onto a carpet 2.0 cm thick. Assuming the force stopping it is constant, find the average force the carpet exerts on the brick. d) If the brick falls onto a 5.0 cm foam rubber pad, what constant force is needed to bring it to rest?

Question

A 9 kg lead brick falls from a height of 1.8 m.  a) Find the momentum as it reaches the ground. b) What impulse is needed to bring the brick to rest? c) The brick falls onto a carpet 2.0 cm thick.  Assuming the force stopping it is constant, find the average force the carpet exerts on the brick.  d) If the brick falls onto a 5.0 cm foam rubber pad, what constant force is needed to bring it to rest?

drwls · Answer

a) momentum = mass * velocity
Compute the velocity from the height it falls. Look up the formula for that or use conservation of energy.
b) Impulse = momentum
c) work done compressing carpet (F*X) = initial kinetic energy
d) Same approach as (c)

I will be happy to critique your thinking

Anonymous · Answer

how the f do you do this

Anonymous · Answer

Suppose a brick has a mass of 4.50 kg. What is the brick's weight at the surface of the Earth