Can the normal force on an object ever do work? Explain.

A light object and a heavy object have the same kinetic energy. Which has the greater momentum? Explain.

The cheetah can reach a top speed of 114 km/h (71 mi/h). While chasing its prey in a short sprint, a cheetah starts from rest and runs 45 m in a straight line, reaching a final speed of 72 km/h. (a) Determine the cheetah’s average acceleration during the short sprint, and (b) find its displacement at t = 3.5 s.

Before the time of Galileo and Newton, some learned scholars thought that a stone dropped from the top of a tall mast of a moving ship would fall vertically and hit the deck behind the mast by a distance equal to how far the ship had moved forward while the stone was falling.

Each bone in the skeletal chain of bones forming your spine is separated from its neighbors by disks of elastic tissue. What happens, then, when you jump heavily onto your feet from an elevated position? Discuss why you think you are a little taller in the morning than at night.

Suppose that you’re in a moving car and the engine stops running. You step on the brakes and slow the car to half speed. If you release your foot from the brakes, will the car spontaneously speed up a bit, or will it continue at half speed and slow due to friction? Defend your answer.

If the velocity of a particle is zero, can the particle's acceleration be non-zero?

Can an object be increasing in speed as its acceleration decreases? If so, give an example. If not, explain.

Can the velocity of an object be negative when its acceleration is positive? What about vice versa?

If one object has a greater speed than a second object. does the first necessarily have a greater acceleration? Explain, using examples.

Does the speedometer of a car measure speed or velocity? Explain.

If you're in a car at rest that gets hit from behind, you can suffer a serious neck injury called whiplash. What does whiplash have to do with Newton's first law?

Now assume that the car (v=25 m/s) is in an accident and is brought to stop over a distance of 12 m. Assuming constant deceleration. how much force will the parent need to exert on the child? Is this force achievable by an average parent?

Determine the work done by the gravitational force on the bob, $\overrightarrow{\mathbf{F}}_{\mathrm{G}}=m \overrightarrow{\mathrm{g}}$, and the work done by the force $\overrightarrow{\mathbf{F}}_{\mathrm{T}}$ that the cord exerts on the bob.