Advertisements
Advertisements
Question
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?
Advertisements
Solution
Given work done = 54,000J, force = 6000 N, 0 = 0°
Now work done = force x displacement x cos 0°
or displacement = `54000/6000` = 9m
APPEARS IN
RELATED QUESTIONS
State and define the S.I. unit of work.
A boy weighing 350 N climbs up 30 steps, each 20 cm high in 1 minute, Calculate:
- the work done and
- power spent.
Work is a scalar quantity because it is a measure of transfer of energy without indicating any direction
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s. Compare the power developed by the persons A and B.
A man raises a box of mass 50 kg to a height of 2 m in 20s, while another man raises the same box to the same height in 50s. Calculated:
- the work done, and
- the power developed by each man. Take g = 10 N kg-1.
State the practical unit mainly used in mechanical engineering and write down its equivalent in watt.
What happens to the power if the time for doing work is reduced from t second to t/10 second?
A machine raises a load of 750 N through a height of 16 m in 5 seconds. Calculate the power at which the machine works.
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person climbs a ladder.
