A Pingpong Ball dropped from a height of 128 m rebounds on each bounce one-half the distance from which it fell.How far will it travel before coming to rest?

Infinite geometric Series

1 Answer
Aug 2, 2018

Initial fall s_1=128m

Next rise and fall s_2=2*1/2*128 m

Next rise and fall s_3=2*(1/2^2)128 m

Next rise and fall s_4=2*(1/2^3)128 m

So total path traveled is

S=sum_(I=1}^(i=oo)s_i

=128+128(1+1/2+1/2^2+..... "up to" oo)

=128+128(1/(1-1/2))

=128+128(1/(1/2))=3*128=384m