If the speed of a body is halved ,what will be the change in its kinetic energy??????????
too easy one....
as we knw that
K.E1 = 1/2 m v12
if the speed is halfed ...then.
let the new kinetic energy be K.E2
and its new velocity ( v2) = v1/2
K.E2 = 1/2 m v22
K.E2 = 1/2 m( v1 / 2)2 ( since v2 = v1 / 2 )
= 1/2 m ( v12 / 4 )
= 1/2 (m v12 ) 1 / 4
= 1/4 [ 1/2 ( m v12 )] ( since K.E1 = 1/2 mv12 )
K.E2 = 1/4 K.E1
Hence , the new kinetic energy must be 1 / 4th of the previous kinetic energy.