Advertisements
Advertisements
Question
When a body is placed on a table top, it exerts a force equal to its weight downwards on the table top but does not move or fall
1) Name the force exerted by the table top
2) What is the direction of the force?
Solution
1) The normal reaction force is exerted by the table top.
2) The force is in the upward direction.
APPEARS IN
RELATED QUESTIONS
A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road.
Who does more work against the force of gravity and why?
State and define the S.I. unit of work.
A man spends 7.4 KJ energy in displacing a body by 74 m in the direction in which he applies force in 2.5 s. Calculate the force applied.
Name the quality which is measured in Wh.
An engine does 54,000 J of work by exerting a force of 6000 N on it. What is the displacement in the direction of the force?
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes. Compare:
- the work, and
- power developed by them.
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes.
How much work each does? Take density of water = 103 kg m-3 and g = 9.8 N kg-1.
State two conditions for work to be done.
Justify the statement. “Power can be expressed as the product of force and velocity.”
For the following scenarios, state whether the work done by gravity is positive, negative, or zero.
A person walks on a levelled road.
