Q.

A tennis ball is dropped on to the floor from a height of 9.8 m. It rebounds to a height of 5.0 m. Ball comes in contact with the floor for 0.2 s. The average acceleration during contact is ________ ms-2. [Given g=10 ms-2]               [2023]


Ans.

(120)

vi=2ghi=2×10×9.8 ↓=14 m/s↓

vf=2ghf=2×10×5 ↑=10 m/s↑

|a→avg|=|Δv→Δt|=240.2=120 m/s2