Unit: Energy
Year: 1989 Question#: 16
Question: A cart rolls down an inclined plane with constant speed as shown in the diagram below. Which arrow represents the direction of frictional force?
(1 ) A
(2 ) B
(3 ) C
(4 ) D
What is this question really asking?
Explanation by: Anna R
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Answer 1
A
INCORRECT
A equals the force of the object due to gravity parallel to the plane and cart.
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Answer 2
B
INCORRECT
B is the direction of gravity pulling down (weight) on the cart.
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C
INCORRECT
C shows the perpendicular direction of gravity to the plane.
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D
CORRECT
D is the direction of frictional force which is between the wheels of the cart and the plane. Frictional force is always in the direction opposite the motion.
return to top What's this question really asking?
How does the direction of frictional force relate to the direction of motion of an object?
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