Question

a ball of mass 100g dropped from a height and reaches ground in 4sec.After hitting the ground,it rebounds with 80%of its K.E. .Find the height at which ball reaches after rrebound.Pls answer according to question.Donot write any unnecessary message for receiving points from brainly.

Answer 1

Given

Mass = 100g and Time = 4 sec

From Newtonian mechanics we know that

V=U+at

here U=o

V= 10x4 = 40m/s ---- this is the velocity with which it strikes the ground

Now, find KE

KE = 1/2mv2 = 1/2x0.1x40x40

                     =80 J

It rebounds with 80% of KE

mgh = 80/100 x 80

0.1 x 10 x h = 64

h = 64 m

Hope this helps