Question

how will the kinetic energy of an object change if its speed halved​

Answer 1

EXPLANATION:-

We know $\sf\;k=\frac{1}{2}mv^2$

k=kinetic  energy

m=mass

v=velocity

SO A.T.Q

If we half the velocity we get velocity=v/2

putting it in the formula we get:-

$\sf\;k=\frac{1}{2}m(\frac{v}{2})^2\\\\k=\frac{1}{2}m(\frac{v^2}{4})\\\\\;Taking\;\frac{1}{4}common\;we\;get:-\\k=\frac{1}{4}(mv^2)\\\\we\;know\;mv^2\;is\;kineitc\;energy\\\\k=\frac{k}{4}\\\\4k=k\\\\k=\frac{1}{4}$

Hence if we half the velocity the kinetic energy will decrease  by 1/4 os it's original kinetic energy