English Medium Class 9 - CBSE Question Bank Solutions for Science

The law of gravitation gives the gravitational force between :

How much work is done when a body of mass m is raised to a height h above the ground?

Is work a scalar or a vector quantity?

What is the work done against gravity when a body is moved horizontally along a frictionless surface?

Fill in the blank with suitable word :
Work is measured as a product of __________ and __________

Fill in the blank with suitable word : 
The work done on a body moving in a circular path is __________

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 __________.

What are the quantities on which the amount of work done depends? How are they related to work?

Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.

A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?

Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.

Give one example each in which a force does (a) positive work (b) negative work, and (c) zero work.

If the work done by a force in moving an object through a distance of 20 cm is 24.2 J, what is the magnitude of the force?

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.