Chapter 11 Vibrations and Waves

Answer sheet

1. When a simple harmonic oscillator is subject to a damping force

a.) the total mechanical energy is conserved.

b.) the amplitude is decreasing but the total mechanical energy remains constant.

c.) the total energy and the amplitude are decreasing.

d.) None of the above is true.

2. When you push a child on a swing, your action is most effective when your pushes are timed to coincide with the natural frequency of the motion.  You are swinging a 30 kg child on a swing suspended from 5 m cables.  Estimate the optimum time interval between your pushes.  Repeat the estimate for a 15 kg child.

3. A tire swing hangs from a branch nearly to the ground.  How could you estimate the height of the branch using only a stopwatch?

4. Are there any thoughts you wish to share, whether they are about this assignment, the reading (what seems impossible, what makes no sense, what you'd like to spend time on in class, what you really found interesting etc) or the course?