Physics

Problem

A pebble is dropped from a bridge

45\,\text{m}

above the surface of a river. Take

g = 9.8\,\text{m/s}^2

. The time taken by the pebble to reach the water is closest to a)

4.5\,\text{s}

3.0\,\text{s}

2.1\,\text{s}

1.5\,\text{s}