Advertisements
Advertisements
Question
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (see the given figure). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Solution
When a force F acts on an object to displace it through a distance S in its direction, then the work done to the body by the force is given by:
Work done = Force × Displacement
W = F × S
Where,
F = 7 N
S = 8 m
Therefore, work done, W = 7 × 8
= 56 Nm
= 56 J
APPEARS IN
RELATED QUESTIONS
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
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.
When is work said to be done by a force?
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
Its moment of a force scalar or a vector quantity?
Is the motion of moon around the earth in circular path an accelerated motion?
A man lifts a mass of 10 kg from the floor to a shelf 4 meter high. If g = 10 ms-2, what is the work done?
Complete the following sentences:
Joule is the unit of .......
Name the physical quantity associated with the 'rate of doing work'.
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
Give an example
Electrical energy changes of sound energy.
Name the material commonly used for the manufacturing of solar cells.
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).
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.