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A nail becomes hot when it is hammered by moving hammer in a plank :

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Important Questions on Work and Energy

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9th CBSE
IMPORTANT
Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 14
A hammer of mass 1 kg falls freely on a nail from a height of 1 m. The kinetic energy of hammer, just before hitting the nail is _____. [g=10 m s-2]
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9th CBSE
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Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 15
A rocket of mass 3×106 kg takes off from a launching pad and acquires a vertical velocity of 1 km s-1 at an altitude of 25 km from launching pad. The potential energy of the rocket is: g=10 m s-2
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Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 16
A rocket of mass 3×106 kg takes off from a launching pad and acquires a vertical velocity of 1 km s-1 at an altitude of 25 km. The kinetic energy of rocket is: 
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Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 17
In a loudspeaker, the:
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9th CBSE
IMPORTANT
Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 18
Chlorophyll in plants converts light energy into:
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9th CBSE
IMPORTANT
Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 1
Give one example in each case, where:
Heat energy changes into kinetic energy.
 
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9th CBSE
IMPORTANT
Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 1

Give one example in each case, where:

Kinetic energy changes into heat energy.

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9th CBSE
IMPORTANT
Core Science Physics For Class 9>Chapter 4 - Work and Energy>EXERCISE>Q 1

Give one example for the given case

Sound energy changes into electrical energy.