Advertisements
Advertisements
Question
What is energy?
Advertisements
Solution 1
The ability or capacity to do work is called energy.
Solution 2
Energy is defined as the capacity to do work. S.I unit of work is Joule.
APPEARS IN
RELATED QUESTIONS
Match the following columns
| COLUMN A | COLUMN B |
| 1. Running water | 1. heat energy |
| 2. Burning | 2. vibrations |
| 3.Energy | 3.atom bomb |
| 4.Sound energy | 4.kinetic energy |
| 5.Nuclear energy | 5.joule |
Select the correct alternatives
When we rub our hands
What do you mean by conservation of mechanical energy? State the condition when does it hold.
Match the following:
| Column A | Column B |
| (a) Needle | (1) class II lever |
| (b) Doorknob | (2) inclined plane |
| (c) Ramp | (3) Class I lever |
| (d) Lemon crusher | (4) Wheel and axle |
| (e) Seesaw | (5) wedge |
Define the term efficiency of a machine.
Define the term 'watt'.
What is the common name of '1 kWh' of electrical energy?
A cell converts one form of energy into another form. Name the two forms.
- Take two aluminium channels of different lengths.
- Place the lower ends of the channels on the floor and hold their upper ends at the same height.
- Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.
- At the moment of releasing the balls, which energy do the balls have?
- As the balls roll down which energy is converted into which other form of energy?
- Why do the balls cover the same distance on rolling down?
Note: The question is wrong. It should be "Why do the balls cover the same distance after rolling down"? - What is the form of the eventual total energy of the balls?
- Which law related to energy does the above activity demonstrate? Explain.
We make useful objects from a variety of substances. Another use of substances is that we get energy from some of them.
There is a car. Its tank is full of fuel but it does not move. Why is that?
Which one of the following requires wind energy?
Find out the form of energy possessed by the following thing.
A rock on the top of a hill
What energy transfer happen in a car engine?
When a body falls freely towards the earth, then its total energy
The work done on an object does not depend upon the
A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back? (g = 10 m s–2)
