Pankaj Bhatt Solutions for Chapter: Work, Energy and Power, Exercise 1: QUESTIONS

An overhead water tank is fixed at the height of 10 m from the ground and has capacity of 500 liters. Calculate the time required to fill the tank from a pump of 0.5 H.P. whose efficiency is 90%.

Define one kilowatt-hour. Find its relation with joule.

A load of 1000 kgf is to be moved on an inclined plane of length 10 m. If the angle of inclination of the plane with the horizontal is $30°$. Calculate the work done against the gravity. $(g=10m{s}^{-2})$

A body of mass 5 kg is pulled from point A to B on an inclined plane ABC. A force of 30 N is applied along the surface AB. Calculate,

(i) the work done by the force in pulling the body.

(ii) the work done against the force due to gravity $[\mathrm{g}=9.8 {\mathrm{ms}}^{-2}]$

(iii) explain the reason for the difference in two works done.

A man runs 50m on horizontal road, then 5 m on an inclined road (inclination 3 in 4). Weight of man is 60 kgf. Calculate total work done by him(Neglect friction).

An overhead water tank of capacity 1000 litres in 30 m above the ground. Calculate total work done in filling this tank. Calculate total time taken by a lift pump of power 5kW to fill the tank.

A steamer boat of 100 HP can move in sea with maximum velocity of 3.43 m/s. Calculate frictional force applied by water on boat.

A power lifter lifts a load of 180 kgf up to height of 2.2 m for 5s. Calculate (i) the work done (ii) power developed by him.