A body of mass 5 kg if moving with a velocity $10 m / s$ . find its kinetic energy. find the ratio of initial kinetic energy and final kinetic energy if (i) its mass is doubled (ii) its velocity is made three times.

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Solution

As we know,
$K E = \frac{1}{2} m v^{2}$
$m = 5 k g & v = 10 m s^{- 1}$
$K E = \frac{1}{2} (5) (10 \times 10) = 250 J$
$c a s e (1) ⟶ R a t i o o f K E w h e n m a s s i s d o u b l e d$
$\frac{K E_{i}}{K E_{f}} = \frac{250}{(500)} = \frac{1}{2}$

$c a s e (i i) w h e n v e l o c i t y i s t h r e e t i m e s$
$\frac{K E_{i}}{K E_{f}} = \frac{250}{(\frac{1}{2} (5) {(3 \times 10)}^{2})} = \frac{250}{2250} = \frac{1}{9}$

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A body of mass 5 kg if moving with a velocity 10 m/s. find its kinetic energy. find the ratio of initial kinetic energy and final kinetic energy if (i) its mass is doubled (ii) its velocity is made three times.​

As we know,KE=12mv2m=5kg&v=10ms−1KE=12(5)(10×10)=250Jcase(1)⟶RatioofKEwhenmassisdoubledKEiKEf=250(500)=12 case(ii)whenvelocityisthreetimesKEiKEf=250(12(5)(3×10)2)=2502250=19

A body of mass 5 kg if moving with a velocity $10 m / s$ . find its kinetic energy. find the ratio of initial kinetic energy and final kinetic energy if (i) its mass is doubled (ii) its velocity is made three times.