How long does it take a brick to reach the ground if dropped from a height of 65 m? What will be its velocity just before it reaches the ground ?
2s, 10m/s
3.64s, 35.67m/s
12s, 120m/s
5s, 20m/s
t=2hg=2×659.8⇒t=3.6 s v=2gh=2×9.8×65; v=35.67 m/s