A ball is dropped on the floor from a height of 10m. It rebounds to a height of 2.5 m if the ball is in contact with floor for 0.01 s then the average acceleration during contact is nearly

Options

A. `700 ms^(-2)`
B. `1400ms^(-2)`
C. `2100 ms^(-2)`
D. `2800 ms^(-2)`

Answer

A

Explanation

(a)`a_("av")=(Deltav)/(Deltat)=(v_(f)-v_(t))/(Deltat)=(sqrt(2gh_(f)))-sqrt(2gh_(i))/(Deltat)`
`=(sqrt(2xx9.8xx2.5)-sqrt(2xx9.8xx10))/(0.01)=700ms^(-2)`