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Question
A machine puts out 100 watts of power for every 1000 watts put into it. The efficiency of the machine isA) 10%.
B) 50%.
C) 90%.
D) 110%.
E) none of the above
Answer
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Related questions
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Q:
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C) acts over a longer distance.
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Q:
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B) 2,000 kg m/s.
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B) 12 kg.
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D) 144 kg.
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Q:
The speed of a 4-kg ball with a momentum of 12 kg m/s is
A) 3 m/s.
B) 4 m/s.
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D) 48 m/s.
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Q:
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B) the normal force becomes less.
C) friction needed to keep it at rest increases.
D) all of the above
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Q:
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A) less than half her weight.
B) half her weight.
C) more than half her weight.
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Q:
When a cannonball is fired from a cannon, which undergoes the greater acceleration?
A) the cannonball
B) the recoiling cannon
C) both the same
Q:
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B) lighter car.
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Q:
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A) somewhat greater than Moon's pull on Earth.
B) the only force acting between Earth and Moon.
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Q:
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A) air resistance acting against the ball.
B) acceleration of the ball.
C) ball's pull on Earth.
D) none of the above
Q:
To produce an acceleration to a system there
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B) may or may not be a net force on the system.
C) must be acceleration outside the system also.
Q:
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the
A) combined weight of the arrow and bowstring.
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Q:
A fast-moving missile soaring overhead possesses
A) speed.
B) force.
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