Question

A car of mass 1650 kg is moving at a uniform
speed of 65 kmph On applying brakes its speed
is reduced to 20 kmph . Find the change in K.E.?

(11th std. q)

Answer 1

INITIAL KE=1650×65×5/18

=29791.66

FINAL KE=1650×20×5/18

=9166.6

CHANGE IN KE=29791.66-9166.66

=20625J

HOPE IT HELPS U..

Answer 2

Explanation:

First

initial K.E=1/2*m*v^2

= 1/2*1650*18.05^2

=825*325.8025

= 268,787.0625 J

similarly

final K.E.=249.5625 J

Now

INITIAL K.E. - FINAL K.E.

=268,787.0625-249.5625

=268,537.5 J

Ans done