Advertisements
Advertisements
Question
What do you understand by work? Is work a scalar or a vector quantity?
Solution
Work is said to be done when a force displaces a body through some distance, in its own direction, i.e.,
Work = Force × Displacement
W = F × d
Work is a scalar quantity.
APPEARS IN
RELATED QUESTIONS
Differentiate between work and power.
What do you mean by equilibrium of a body?
A pump is used to lift 600 kg of water from a depth of 75 m in 10s. Calculate:
- The work done by the pump,
- the power at which the pump works, and
- The power rating of the pump if its efficiency is 40%. (Take g = 10m s-2).
`["Hint" : "Efficiency" = "useful power"/"power input"]`
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.
State the practical unit mainly used in mechanical engineering and write down its equivalent in watt.
Calculate the work done when:
A car is moved on a rough road through 30 m against a frictional resistance of 75 N.
State the C.G.S. unit of work. How it is related to its S.I. unit?
For the following scenarios, state whether the work done by gravity is positive, negative, or zero.
A car in neutral gear is coming down the slope.
A man raises a box of mass 50 kg to a height of 2 m in 20 s, while another man raises the same box to the same height in 50 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1
