[2011 Pre]
Solution:
Concept: Free fall under gravity.
Formula: \(v^2 = u^2 + 2gh\).
Solution: Given \(u=0\) (dropped), \(h=20\text{ m}\,\text{ }g=10\text{ m/s}^2\). \(v^2 = 0^2 + 2(10)(20) = 400\). So, \(v = \sqrt{400} = 20\text{ m/s}\).
A boy standing at the top of a tower of \(20\text{ m}\text{ height drops a stone. Assuming } g = 10\text{ m/s}^2\text{, the velocity with which it hits the ground is:}\)
Leave a Reply