Work CHAPTER -9
.5 Force, Work, and Potential Energy
.6 Finding Force from Potential Energy
15. A particle moves in a vertical plane along a closed path, starting at A and eventually returning to its starting point. How much work is done on the particle by gravity? Explain.
16. a. If the force on a particle at some point in space is zero, must its potential energy also be zero at that point? Explain.
b. If the potential energy of a particle at some point in space is zero, must the force on it also be zero at that point? Explain.
17. The graph shows the potential-energy curve of a Energy particle moving along the x-axis under the influence of a conservative force.
a. In which
intervals of x is the force on the
to the right?
b. In which intervals of
x is the force on the particle
to the left?
c. At what value or values of x is the magnitude of the force a maximum?
11-10 CHAPTER 11 Work
d. What value or values of x are positions of stable equilibrium?
e. What value or values of x are positions of unstable equilibrium?
f. If the particle is released from rest at x = 0 m, will it reach x = 10 m? Explain.
.7 Thermal Energy
1 A car traveling at 60 mph slams on its brakes and skids to a halt. What happened to the kinetic energy the car had just before stopping?
2 What energy transformations occur as a skier glides down a gentle slope at constant speed?