Question

how long will a stone take to fall to the ground from the top of a hill 80m high. what is its final velocity[g=10m/s-2]

Answer 1

Hi✌️✌️

intial velocity(u) = 80 m

height (h) = 80m

acceleration due to gravity = 9.8 ms-2

According to the equations of motion,

h = ut+1/2gt^2

80 = 0×t+1/2×9.8×t^2

80 = 1/2×9.8t^2

80 = 4.9t^2

80/4.9 = t^2

800/49 = t^2

t^2 = 16.32

t = root of 16.32

t = 4.03 s

v is the final velocity

v = u+gt

v = 0+9.8×4.03

v = 9.8×4.03 = 39.494 = 39.5 m/s

Therefore time taken is 4.03s and the final velocity v acquired by the stone is 39.5m/s

‼️i hope it will help u ‼️