Question

a stone is dropped down a deep well from rest the well is 50 metre deep how long will it take to reach the bottom of the well take acceleration= 9.8 answer will be 3.2 sec
please give explanation​

Answer 1

The given

initial velocity = 0

acceleration = 9.8m/s^2

height = 50m

$h = ut + \frac{1}{2} a {t}^{2} \\ 50 = 0 \times t + \frac{1}{2} \times 9.8 \times {t}^{2} \\ 5 0 = 4.9 \times {t}^{2} \\ \frac{500}{49} = {t}^{2} \\ t = \sqrt{ \frac{500}{49} } \\ t = \frac{ \sqrt{500} }{7} \\ t = \frac{22.36}{7} \\ t = 3.19 \\ t = 3.2$