Chapter 6 Work and Energy

Answer sheet.

1.  A skydiver whose parachute is fully deployed is descending at constant speed.  Describe what is happening to her kinetic energy, her potential energy, and her total mechanical energy as she falls.  Is any work being done?  If yes, where does it go?

2.  A force of 100N, acting over a distance of 10 m, increases the kinetic energy of a moving object by 500J.  This information is sufficient to conclude that

a.) the object was accelerated.

b.) there was friction present.

c.) the potential energy changed.

d.) all of the above.

3. A good professional baseball pitcher throws a ball straight up in the air.  Estimate how high the ball will go.  (A good throw can reach 90 mph.)

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?