Chapter 8 Review Questions

In walking, people normally bend their knees. Why?

(a) it is easier to swing their legs because bending lowers the rotational inertia of their legs

(b) it is easier to swing their legs because bending increases the rotational inertia of their legs

Which is harder to stop? A rotating rod with its mass predominantly at the

(a) middle of the rod

(b) ends of the rod

(c) neither of the above

A ball is at rest on a horizontal table. It is in a state of equilibrium.

(a) neutral

(b) stable

(c) unstable

(d) both (a) and (b)

(e) both (a) and (c)

Which of the following forces is a pseudo force?

(a) tension in a rope

(b) force of gravity

(c) centripetal

(d) friction

(e) centrifugal

What is the angular momentum of a 6 kg mass traveling with a speed of 6 m/s in a circle of radius of 12 m?

(a) 432 kg·m²/s

(b) 12 kg·m²/s

(c) 24 kg·m²/s

(d) 144 kg·m²/s

(e) 36 kg·m²/s