Section 5.2
Friction
Practice Test
1.
A sled of mass 40.0 kg is pulled along flat, snow-covered ground. The static friction coefficient is 0.28, and the kinetic friction coefficient is 0.08. What force is needed to keep the sled moving at a constant velocity?
a.
31 N
b.
3900 N
c.
3.2 N
d.
310 N
Hint
2.
A sled of mass 40.0 kg is pulled along flat, snow-covered ground. The static friction coefficient is 0.28, and the kinetic friction coefficient is 0.08. What force will be needed to start the sled moving?
a.
147 N
b.
31 N
c.
110 N
d.
392 N
Hint
3.
When there is no relative motion between two surfaces, the force exerted by one surface on the other is called __________.
a.
resistance
b.
the static friction force
c.
the kinetic force
d.
kinetic friction
Hint
4.
The __________ is the force exerted on one surface by another when the surfaces are in relative motion.
a.
kinetic coefficient
b.
apparent weight
c.
static friction force
d.
kinetic friction force
Hint
