Advertisements
Advertisements
प्रश्न
Select the correct alternatives
When we rub our hands
विकल्प
kinetic energy changes into potential energy
mechanical energy changes into heat energy
potential energy changes into kinetic energy
heat energy changes into mechanical energy.
Advertisements
उत्तर
mechanical energy changes into heat energy
APPEARS IN
संबंधित प्रश्न
A certain household has consumed 250 units of energy during a month. How much energy is this in joules?
Write true or false of the following statement.
Potential energy changes into kinetic energy when it is put to use
Fill in the blank
Cooking gas converts _______ energy into heat energy.
Select the correct alternatives
When a bulb lights up on passing current, the change of energy is
State the unit of energy and define it.
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 |
- 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.
If the energy of a ball falling from a height of 10 metres is reduced by 40%, how high will it rebound?
The capacity that an object has for doing work is called ______.
Which one of the following is not the unit of energy?
