Transcript document

Review for:
Unit 6 – Momentum, Work,
Power, Machines, Energy
#1 Which of these is the
best example of potential
energy?
A. A ball rolling across the floor
B. A runner lying on the ground after a race
C. A wind-up toy with the spring tightly
wound
D. Jack and Jill at the bottom of their hill
#2 Kinetic energy is the
energy an object has
because of its…
A.
B.
C.
D.
Location
Density
Motion
tension
#3 Which will do more damage
because of greater kinetic
energy – a 300kg tackle moving
at 2 m/s or a 150kg linebacker
moving at 4 m/s?
A. The tackle
B. The line backer
C. neither
#4 Power is scientifically
defined as the…
A. Force on an object time the distance the
object moves
B. Force on an object times the time of
application
C. Work done on or by an object per unit
time
D. Energy used by an object times the time.
#5 The SI units for energy,
work, and power (in that
order) are…
A.
B.
C.
D.
Joule, watt, joule
Joule, joule, watt
Joule, watt, watt
Watt, watt, joule
#6 The kinetic energy of the
ball at position “a” is…
A. 500 J
B. 0 J
C. Impossible to
determine
#7 If friction is negligible, the
ball’s kinetic energy at point
“d” will be…
A. 500 J
B. 0 J
C. Impossible to
determine
#8 When the ball reaches
point “b”, its PE will have ___
and its KE will have ___.
A.
B.
C.
D.
Increased; decreased
decreased; increased
Increased; increased
Decreased; decreased
#9 Which of these statements
about machines is false?
A. Machines decrease the amount of work
needed to do a job
B. Machines decrease the force needed to get
the work done
C. Machines increase the distance moved in
doing work
D. Because of friction, the work input is more
than work output
#10 When work is done by an
object, the object’s PE or KE…
A. Increases
B. Decreases
C. Stays the same
#11 A screw is a(n)…
A.
B.
C.
D.
Pulley
Lever
Inclined plane
Wheel and axle
#12 Momentum is…
A.
B.
C.
D.
Moving inertia
Mass times volume
Measured in newton-meters
All of these
#13 When an object’s velocity
is doubled, its kinetic energy
will be ____ and its
momentum will be ____.
A.
B.
C.
D.
Doubled; doubled
Doubled; quadrupled
Quadrupled; quadrupled
Quadrupled; doubled
#14 _____ have perfectly
elastic collisions.
A.
B.
C.
D.
Gas molecules
Hockey pucks
Billiard balls
All of these
#15 The momentum of a
soccer player sitting on the
bench…
A. Depends on his/her mass
B. Is different from the momentum of a
basketball player sitting on the bench
C. Is zero
D. Depends on how fast he/she was going
before he/she sat down
#16 Granny whizzes around a skating rink
and is suddenly confronted with little
Ambrose at rest directly in her path. Rather
than knock her over, Granny picks her up
and continues in motion without “breaking”
The collision between Granny and Ambrose
is...
A. Elastic
B. Inelastic
#17 Granny whizzes around a skating rink
and is suddenly confronted with little
Ambrose at rest directly in her path. Rather
than knock her over, Granny picks her up
and continues in motion without “breaking”
After the collision, Granny’s speed will…
A. Increase
B. Decrease
C. Stay the same
#18 Granny whizzes around a skating rink
and is suddenly confronted with little
Ambrose at rest directly in her path. Rather
than knock her over, Granny picks her up
and continues in motion without “breaking”
According to the Law of Conservation of
Momentum…
A. Granny’s momentum cannot change
B. Ambrose’s momentum cannot change
C. The total momentum of the two cannot
change
D. All of these
#19 When a bug hits the
windshield of a bus, the bug
experiences the greater…
A.
B.
C.
D.
Time of impact
Force of impact
Change in momentum
Change in velocity
#20 What is necessary to
change the momentum of an
object?
A. A net, external force applied for a period of
time
B. An impulse
C. Both a and b
D. Neither a nor b
#21 Momentum is conserved in
____ collisions, but KE is
conserved only in ____ collisions.
A.
B.
C.
D.
Elastic; inelastic
All; elastic
Inelastic; elastic
All; inelastic
#22 What’s the power of a machine
that lifts a 12N object 4.0m in 6.0s?
A.
B.
C.
D.
48 J
2.0 W
8.0 W
3.0 W
Questions?
Comments?
Criticisms?
Concerns?
Complaints?