Question

A stone is dropped is freely in the river from a bridge.its take 5 sec to touch the water surface in the river .calculate (1)the height of river bridge from water level.(2)the distance covered by stone in last second (g=9.8m/s square)

Answer 1

[1]
S = ut + 0.5at²

H = 0 + 0.5gt²
= 0.5 × 9.8 m/s² × (5 s)²
= 122.5 m
Height of the bridge is 122.5 m
________________

[2]
Distance covered in last second = Distance covered in 5th second

S = u + a(n - 0.5)
= 0 + g(n - 0.5)
= 9.8 m/s² × (5 - 0.5)
= 44.1 m
Distance covered in last second is 44.1 m

Answer 2

Here is the answer
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