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प्रश्न
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उत्तर
K.E ,K = `1/2`mv²
If speed is doubled;
K.E , K = `1/2` m (2v)²
or K' = 4 x `1/2` mv² = 4K
Thus K.E becomes four times
Thus if initially the K.E is 5J after increasing the speed twice, its k.E will become 4 x5 = 20 J.
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संबंधित प्रश्न
How is work related to energy?
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Name the physical quantity whose MKS units are kgm2s-3.
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
A canon ball of mass 500g is fired with a speed of 15m/s-1. Find: its momentum.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
