Advertisements
Advertisements
Question
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
Solution
Work is done only in case of a boy climbing up a stair case.
APPEARS IN
RELATED QUESTIONS
Define 1 J of work.
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
When does a force perform work?
When is work said to be done by a force?
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
What are the quantities on which the amount of work done depends? How are they related to work?
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
State the conditions of equilibrium for a rigid body.
Explain the difference between a uniform linear motion and a uniform circular motion.
Is the motion of moon around the earth in circular path an accelerated motion?
Name the force acting away from the centre of circular path.
Is power a scalar quantity?
Can every force produce work?
Can work done be zero even if force acts on the body?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
Give an example
Electrical energy changes of sound energy.
A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg−1).
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
An engine is pulling a train.
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
