SCIENCE
PHYSICAL SCIENCES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -The weight lifter applies a large force to hold the barbell over his head. Because the barbell is motionless, no work is done on the barbell.
Detailed explanation-2: -A weightlifter holds a 100 kg barbell above her head. Is work done? Yes because there is a force applied to the barbell and the force causes a displacement of the barbell.
Detailed explanation-3: -There is no displacement of weight when he holds it. Hence, no work is done.
Detailed explanation-4: -The correct answer is Boy pushing wall in a room. Boy pushing the wall in the room is not an example of work done. When a boy pushes a wall, he is applying force on the wall.
Detailed explanation-5: -The object moves as a force is applied. The direction of the object’s motion is the same as the direction of the force applied.