Transcript College Physics

Chapter 7 – part A
Potential
Potential Energy
Exercise 7.32
32.
A single conservative force
acting
on a particle varies as

F  (Ax  Bx2 ) iˆ N, where A and B are
constants and x is in meters.
(a) Calculate the potential energy
function U(x) associated with this force,
taking U = 0 at x = 0.
(b) Find the change in potential energy of
the system and the change in kinetic
energy of the particle as it moves from
x = 2.00 m to x = 3.00 m.
Exercise 7.15
15.
A force acting on a particle
moving
in the xy plane is given by

F  (2 yiˆ  x 2 ˆj) N, where x and y are in
meters. The particle moves from the
origin to a final position having
coordinates x = 5.00 m and y = 5.00 m
as shown in Figure. Calculate the
work done by the force on the particle
as it moves along (a) OAC, (b) OBC,
and (c) OC. (d) Is conservative or
nonconservative? Explain.
Exercise 7.17
17.
A block of mass 0.250 kg is
placed on top of a light vertical spring
of force constant 5 000 N/m and
pushed downward so that the spring is
compressed by 0.100 m. After the
block is released from rest it travels
upward and then leaves the spring. To
what maximum height above the point
of release does it rise?
Exercise 7.28
28.
A 50.0-kg block and 100-kg block
are connected by a string as shown in
Figure P7.28. The pulley is frictionless
and of negligible mass. The coefficient of
kinetic friction between the 50-kg block
and incline is 0.250. Determine the
change in the kinetic energy of the 50-kg
block as it moves from A to B, a distance
of 20.0 m.
Exercise 7.5


vi
5. A bead slides without friction
around a loop-the-loop. The bead is
released from a height h = 3.50R.
(a) What is its speed at point A?
(b) How large is the normal force on
it if its mass is 5.00 g?