Question 1

To prevent it from tumbling in flight, a projectile such as a football is sent off spinning. The physical principle involved is

Accepted Answer

A)   conservation of energy.
B)   conservation of linear momentum.
C)   conservation of angular momentum.
D)   the first law of motion.E) B) and C)
F) A) and C)

Question 2

The minimum force that must be applied to a machine with a mechanical advantage of 5 in order to lift a 100-kg crate is

Accepted Answer

A)   20 N.
B)   196 N.
C)   500 N.
D)   4900 N.E) All of the above
F) A) and D)

Question 3

A bowling ball rolling on level ground at the speed v strikes a basketball at rest. The basketball moves off in the original direction of the bowling ball

Accepted Answer

A)   with the speed v while the bowling ball stops.
B)   faster than v while the bowling ball continues slower than v.
C)   with the speed v while the bowling ball moves backward.
D)   together with the bowling ball at the same speed of less than v.E) B) and C)
F) All of the above

Question 4

The speed of a 1000-kg car whose KE is 450 kJ is

Accepted Answer

A)   21 m/s.
B)   30 m/s.
C)   45 m/s.
D)   900 m/s.E) C) and D)
F) A) and D)

Question 5

When a skater pulls in her arms to turn faster, her angular momentum

Accepted Answer

A)   increases.
B)   decreases.
C)   remains the same.
D)   Any of these choices, depending on circumstances.E) A) and B)
F) B) and D)

Question 6

An 800-kg car moving at 80 km/h overtakes a 1200-kg car moving at 40 km/h in the same direction. If the two cars stick together, the wreckage has an initial speed of

Accepted Answer

A)   8 km/h.
B)   40 km/h.
C)   56 km/h.
D)   60 km/h.E) C) and D)
F) B) and D)

Question 7

What never changes when two or more objects collide is

Accepted Answer

A)   the momentum of each object.
B)   the kinetic energy of each object.
C)   the total momentum of all the objects.
D)   the total kinetic energy of all the objects.E) A) and C)
F) C) and D)

Exam 3: Energy

A bowling ball rolling on level ground at the speed v strikes a basketball at rest. The basketball moves off in the original direction of the bowling ball

Correct Answer
verified

An 800-kg car moving at 80 km/h overtakes a 1200-kg car moving at 40 km/h in the same direction. If the two cars stick together, the wreckage has an initial speed of

Correct Answer
verified

The speed of a 1000-kg car whose KE is 450 kJ is

Correct Answer
verified

When a skater pulls in her arms to turn faster, her angular momentum

Correct Answer
verified

What never changes when two or more objects collide is

Correct Answer
verified

The minimum force that must be applied to a machine with a mechanical advantage of 5 in order to lift a 100-kg crate is

Correct Answer
verified

To prevent it from tumbling in flight, a projectile such as a football is sent off spinning. The physical principle involved is

Correct Answer
verified

Exam 3: Energy

A bowling ball rolling on level ground at the speed v strikes a basketball at rest. The basketball moves off in the original direction of the bowling ball

Correct AnswerverifiedShow Answer

An 800-kg car moving at 80 km/h overtakes a 1200-kg car moving at 40 km/h in the same direction. If the two cars stick together, the wreckage has an initial speed of

Correct AnswerverifiedShow Answer

The speed of a 1000-kg car whose KE is 450 kJ is

Correct AnswerverifiedShow Answer

When a skater pulls in her arms to turn faster, her angular momentum

Correct AnswerverifiedShow Answer

What never changes when two or more objects collide is

Correct AnswerverifiedShow Answer

The minimum force that must be applied to a machine with a mechanical advantage of 5 in order to lift a 100-kg crate is

Correct AnswerverifiedShow Answer

To prevent it from tumbling in flight, a projectile such as a football is sent off spinning. The physical principle involved is

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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