MEDIUM
9th CBSE
IMPORTANT
Earn 100

A battery lights a bulb. Describe the energy changes involved in the process.

Important Questions on Work and Energy

MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 4
Certain force acting on a 20 kg mass changes its velocity from 5 m s–1 to 2 m s–1. Calculate the work done by the force. 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 5
A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer. 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 6
The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why? 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 7
 What are the various energy transformations that occur when you are riding a bicycle? 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 8
Does the transfer of energy take place when you push a huge rock with all your might and fail to move it?  Where is the energy you spend going? 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 9
 A certain household has consumed 250 units of energy during a month. How much energy is this in joules?  
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 10
An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when the object is halfway down. 
MEDIUM
9th CBSE
IMPORTANT
SCIENCE TEXTBOOK FOR CLASS IX>Chapter 11 - Work and Energy>Exercises>Q 11
What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.