Advertisements
Advertisements
Question
A man lifts a mass of 20 kg to a height of 2.5 m. Assuming that the force of gravity on 1 kg mass is 10 N, find the work done by the man.
Advertisements
Solution
Mass = 20 kg h = 2.5 m
Force of gravity on a mass of 1 kg = 10 N
Force of gravity on a mass of 20kg
F = mg = 20 × 10 = 200 N
Work done in lifting the mass to height h = 20 m is
W = F × h
= 200 N × 2.5 m
= 200 × 25/10 =500 J
APPEARS IN
RELATED QUESTIONS
Give reasons for the following. No work is done if a man is pushing against a wall.
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 :
1 joule is the work done when a force of 1 __________ moves an object through a distance of one __________ in the direction of __________.
Does the earth move around the sun with a uniform velocity?
How many joules are there in 1 mega joule?
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
What is the difference between renewable and non-renewable resources?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
