Question

If the mass of a body is reduced to half and its velocity is doubled
calculate me perantage increase in ke?
pl
Geral
ta
lal​

Answer 1

Explanation:

Let the Mass of the body be = m

Velocity of the body = v

$initial \: kinetic \: energy = \frac{1}{2}m {v}^{2}$

ATQ,

Mass of the body = m/2

Velocity of Body = 2v

$new\: kinetic \: energy = \frac{1}{2} (\frac{m}{2}) {(2v)}^{2}$

$= \frac{1}{2}( \frac{m}{2})(4 {v}^{2}) = 2( \frac{1}{2}m {v}^{2})$

$new \: kinetic \: energy = 2(initial \: kinectic \: energy)$

Increase %

$\frac{new \: ke - initial \: ke}{initial \: ke} \times 100$

$\frac{2 (\frac{1}{2}m {v}^{2}) - 1(\frac{1}{2}m {v}^{2})}{ \frac{1}{2}m {v}^{2} } \times 100$

$\frac{ \frac{1}{2}m {v}^{2}}{ \frac{1}{2}m {v}^{2} } \times 100 = 100\%$

Therefore , the percentage increase in KE is 100 %

I hope it helps you. If you have any doubts, then don't hesitate to ask.