chapter 3 RAT

Question 1

A freight train rolls along a track with considerable momentum. If it then rolls at the same speed but has twice as much mass, its momentum is now
A. zero.
B. twice as large.
C. four times as large.
D. unchanged.

Answer 1

B. twice as large

Question 2

In the absence of external forces, momentum is conserved in
A. an elastic collision.
B. an inelastic collision.
C. either an elastic or an inelastic collision.
D. neither an elastic nor an inelastic collision.

Answer 2

C. either an elastic or an inelastic collision

Question 3

If the running speed of Fast Freda doubles, what also doubles is her
A. momentum.
B. kinetic energy.
C. both of these
D. neither of these

Answer 3

A. momentum

Question 4

How much work is done on a 200-kg crate that is hoisted 2 m in a time of 4 s?
A. 400 J
B. 1000 J
C. 1600 J
D. 4000 J

Answer 4

D. 4000 J

Question 5

A circus diver drops from a high pole into water far below. When he is halfway down,
A. his potential energy is halved.
B. he has gained an amount of kinetic energy equal to half his initial potential energy.
C. his kinetic energy and potential energy are equal.
D. all of these

Answer 5

D. all of these

Question 6

A bicycle that travels twice as fast as another when braking to a stop will skid
A. twice as far.
B. four times as far.
C. eight times as far.
D. depends on the bike’s mass.

Answer 6

B. four times as far

Question 7

The initial source of energy for wind power, fossil fuels, and biomass is
A. nuclear.
B. matter itself.
C. solar.
D. photovoltaic.

Answer 7

C. solar

Question 8

A machine cannot multiply
A. force.
B. distance.
C. energy.
D. none of these; that is, it can multiply all of them.

Answer 8

C. energy