1.
A 75 kg man climbs a staircase with a height of 4 m. What is the work done against gravity?
A
300 J
B
750 J
C
3000 J
D
4000 J
View Answer
Correct Answer: C — 3000 J
Explanation:
Work done = mgh = 75 × 10 × 4 = 3000 J.
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A 75 kg man climbs a staircase with a height of 4 m. What is the work done against gravity?
300 J
750 J
3000 J
4000 J
Correct Answer: C — 3000 J
Explanation:
Work done = mgh = 75 × 10 × 4 = 3000 J.
What is the condition for work to be done by a force?
The force must be zero
There must be a displacement in the direction of the applied force
The object must be at rest
The displacement must be perpendicular to the force
Correct Answer: B — There must be a displacement in the direction of the applied force
Explanation:
Work is done when a force causes displacement in its direction.