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?

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

how the f do you do this

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

To find the answers to these questions, we'll need to use some principles from physics. Let's go step by step.

a) Find the momentum as it reaches the ground:
The momentum (p) of an object is given by the product of its mass (m) and velocity (v). The velocity of the falling brick can be found using the concept of free fall. Since the brick is falling from a height of 1.8 m, we can use the equation for the final velocity of an object in free fall:

v = √(2gh)

where g is the acceleration due to gravity (approximately 9.8 m/s^2) and h is the height (1.8 m). Plugging in the values, we can calculate the velocity. Once we have the velocity, we can calculate the momentum using the mass of the brick (9 kg):

p = m * v

b) Find the impulse needed to bring the brick to rest:
Impulse (J) is defined as the change in momentum of an object. Since the initial momentum of the brick is its momentum when it reaches the ground and its final momentum is zero when it comes to rest, the impulse can be calculated as:

J = -p

Note that the negative sign indicates that the impulse is in the opposite direction of the object's momentum.

c) Find the average force the carpet exerts on the brick:
To find the average force exerted by the carpet, we can use Newton's second law, which states that force (F) is equal to the rate of change of momentum:

F = Δp / Δt

In this case, since the time it takes to stop can be considered negligible, we can approximate Δt as 0. Therefore, the average force can be calculated as:

F = Δp / 0 = ∞

However, it is important to note that this calculation does not account for the deformations occurring during the collision with the carpet. If we assume the deceleration is constant, we can estimate the average force using the concept of average acceleration:

a = Δv / Δt

where Δv is the change in velocity. From the previous question, we know the final velocity of the brick is 0 m/s. With this information, we can calculate the average deceleration of the brick during its travel to rest using the equation above. Then we can apply Newton's second law to calculate the average force exerted by the carpet on the brick:

F = m * a

d) Find the constant force needed to bring the brick to rest on a foam rubber pad:
Similar to the previous question, we can use Newton's second law to find the constant force required to bring the brick to rest. We calculate the average deceleration of the brick using the initial velocity from part a (obtained using the same equation for free fall) and the final velocity of 0 m/s. With the average deceleration, we can calculate the force using Newton's second law:

F = m * a

Keep in mind that this calculation does not take into account the deformations or any other factors that could affect the force required to bring the brick to rest.