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Question
Heat a copper wire and its electric resistanceA) decreases.
B) remains unchanged.
C) increases.
Answer
This answer is hidden. It contains 1 characters.
Related questions
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If the speed of a bicycle is reduced to half before skidding to a stop, it will skid
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B) one-fourth as far.
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Q:
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C) acts over a longer distance.
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If a Ping-Pong ball and a golf ball both move in the same direction with the same amount of kinetic energy, the speed of the Ping-Pong ball must be
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When you jump from an elevated position you usually bend your knees upon reaching the ground, which makes the time of the contact about 10 times that of a stiff-legged landing. In this way the average force your body experiences is
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Q:
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Q:
It is correct to say that impulse is equal to
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Q:
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B) 2,000 kg m/s.
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Q:
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B) 12 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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Q:
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A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water leaves the west bank. To land at a point due east of its starting point, the boat must be pointed
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As the sloped surface supporting a shoe becomes steeper
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B) the normal force becomes less.
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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:
A pair of toy freight cars, one twice the mass of the other, fly apart when a compressed spring that joins them is released. Acceleration will be greater for the
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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.
C) equal in magnitude to the force that Moon pulls on Earth.
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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
A) must be a net force on the system.
B) may or may not be a net force on the system.
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Q:
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the
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Q:
A fast-moving missile soaring overhead possesses
A) speed.
B) force.
C) both of these
D) neither of these