Advertisements
Advertisements
Question
A water pump raises 50 litres of water through a height of 25 m in 5 s. Calculate the power of the pump required.
(Take g = 10 N kg-1 and density of water = 1000 kg m-3)
Solution
Mass of 50 litre of water = 50 kg
∵ 1cm3 of water = 1g
∵ 1000cm3 = 1 Lit. = 1kg
height = 25 m, t = 5 s, g = 10 Nkg-1
Power supplied by pump
= `(mgh)/t`
= `(50 xx 10 xx 25)/5`
= 2500 W
APPEARS IN
RELATED QUESTIONS
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?
Differentiate between energy and power.
State the energy transformation on the following:
Electricity is obtained from solar energy.
How much work is done when a body of mass m is raised to a height h above the ground?
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
Name five appliances or machines which use an electric motor.
The work done on an object does not depend on ______.
What is the work done when the object acted upon by a force remains at rest?
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
Name the physical quantity associated with the 'rate of doing work'.
Calculate the amount of work done by a child carrying a bag of 20 kg when he moves a distance of 40 m in
(a) Vertical direction, and
(b) Horizontal direction
Give an example
Electrical energy changes of sound energy.
Define force. Is force a scalar or a vector quantity?
Can two agents, doing the same work, have different power?
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
What should be the characteristic of a source of energy?
________ is said to be done when a force is acting on it.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A donkey is carrying a load on its back.
