Homework # 3 Please SHOW ALL of your WORK!

Due 03/03/2023

1. Consider two puppies lying on top of each other, each with a mass of 2.3 kg and the bottom puppy is on the floor.

a) What is the normal force acting on the top puppy from the bottom puppy?

b) What is the normal force acting on the bottom puppy from the floor?

2. You want to lift a 1300 kg safe from the ground to a vault at the top of a 50 m tall building. You have two options to use: a 600 m long ramp or a pulley system with 4 pulleys.

a) Determine the work done in both scenarios.

b) Which scenario would be 'easier' to do?

3. Consider a 3.7 kg cat that falls from a 7 m tall window ledge. Determine how fast the cat is moving when it gets to the ground using only energy equations, no kinematics equations. Recall that energy is neither created nor destroyed such that the amount of energy the cat has when it is at a height of 7 m is the same as when it is moving at a currently unknown velocity v when it is reaches the ground.

4. Consider a 97 kg baseball player that slides towards home plate with an initial speed of 7.8 m/s and comes to a stop 1.79 s later. Determine

a) the acceleration felt by the player during that time and

b) the work done on the player during the slide.