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प्रश्न
When a body falls freely towards the earth, then its total energy
विकल्प
increases
decreases
remains constant
first increases and then decreases
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उत्तर
remains constant
Explanation:
When a body falls freely towards the earth, its potential energy decreases which in turn increases the kinetic energy. Therefore, its total energy remains constant.
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संबंधित प्रश्न
Write true or false of the following statement.
A gum bottle lying on a table has no energy.
Write true or false of the following statement.
One form of energy cannot be converted into another form.
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 |
Name the quantity whose unit is :
(a) kilowatt
(b) kilowatt-hour
- 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.
Can you tell?
When can we say that displacement has taken place?
Can you tell?
What should be taken into account for measuring work?
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?
Running water possesses ______.
The weight of a person on planet A is about half that on the earth. He can jump up to 0.4 m in height on the surface of the earth. How high he can jump on planet A?
