Work


 
 
Concept Explanation
 

Work

Work: The word ‘work’ has many different meanings. In physics, however, it has a special meaning. When a force acts on an object moves, we say that the force has one work on the object.

When an apple falls from a tree, the force of attraction of the earth does work on the apple. Work is always done by a force. The work done by a force acting on an object to equal to the product of the force and the displacement of the object in the direction of the force. We assume here that the force remains constant during the whole displacement. Note that both force and displacement have directions, i.e., they are vectors. Work, which is a product of force and displacement, does not have a direction. It is a scalar quantity.

Work Done = Force X Displacement

Q. A force of 10 N causes a displacement of 2m in a body in its own direction. Calculate the work done by the force .

Solution : The work done by the force W = F x s = 10 N x 2 m = 20 J

Q. How much force is applied on the body when 150 joule of work is done in displacing the body through a distance of 10 m in the direction of force?Solution:     Work done         W = F x s  

                we can say that   F:=:frac{W}{s}                                            F:=:frac{150}{10}:N:=: 15; N   

 

 

Sample Questions
(More Questions for each concept available in Login)
Question : 1

A carton is pulled along the ground for a distance of 5 m. If the force of friction is 79 N, then the work done is

Right Option : D
View Explanation
Explanation
Question : 2

A car moving along a straight level road with constant speed. Then

Right Option : B
View Explanation
Explanation
Question : 3

A man pushes a wall but fails to displace it.He does __________________.

Right Option : C
View Explanation
Explanation
 
 
 


Students / Parents Reviews [20]