# A guy drops a rock from a bridge and it hits the river 3.60s later. How high is the bridge?

Nov 14, 2015

The formula that will answer this question is
$d = {v}_{i} t + \frac{1}{2} a {t}^{2}$

#### Explanation:

The information you have been given:
${v}_{i}$ = 0 m/s (the rock was not previously moving)
$t$ = 3.60 s
$a = 9.80 \frac{m}{s} ^ 2$, as it is resulting from gravity

Plug these values into your formula. This should give you an answer of 63.50 m.