An elastic sphere is dropped from a height of 4 m upon a fixed horizontal plane. If coefficient of restitution be 0.8 and and value of g = 9.8 m/s, then

Options

A. total distance covered by the particle before it has finished rebounding is 13 m.
B. total distance covered by the particle before it has finished rebounding is `~~` 18 m.
C. duration for which the sphere rebounds is `~=` 8 s
D. duration for which the sphere rebounds is `~=` 3 s

Answer

B, C

Explanation

`s=h+2e^(2)h+2e^(4)h+…+`
`T=sqrt((2h)/(g))+2e sqrt((2h)/(g))+2e^(2)sqrt((2h)/(g))+…`
`therefore` (B) & (C )