Advertisements
Advertisements
Question
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.
Advertisements
Solution
- An engine applies force to pull the train. This allows the train to move in the direction of force.
- Therefore, there is a displacement in the train in the same direction.
- Hence, work is done by the engine on the train.
RELATED QUESTIONS
A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?
Power spent by a body depends on the time for which it does work.
Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.
P, Q and R are three forces which act as shown in fig.

The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
A boy does work when he pushes against a brick wall. (yes/no).
Distinguish between work and power.
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
One labourer carried four pans of road metal through a distance of 100 metres. If he carries two pans of road metal through a 200 metre distance ______ work will be done.
