Question

A stone is thrown downward making an angle of 30degrees with horizontal with a velocity of 10m/s from top of a bridge. If this stone strikes after 2s with the water ,then find height of a bridge.​

Answer 1

Explanation:

hope this will help you

Answer 2

15.12 m

Explanation:

$here \: \\ u = 10 \: m {s}^{ - 1} \\ \theta = 30 \degree \\ t = 2 \\ g = 10 \\ h = \frac{ {10}^{2} { \sin }^{2} \theta }{2g} = \frac{ {10}^{2} { \sin }^{2} 30 }{20} \\ h = 4.88 \: m \\ from \: that \: height \\ u = 0 \\ s = \frac{1}{2} \times 10 \times {2}^{2} = 5 \times 4 = 20 \: m \\ height \: of \: bridge \: from \: river = 20 - 4.88 = 15.12 \: m$

hope it clear!