# At a construction site a pipe wrench struck the ground with a speed of 24m/s. (a) From what height was it inadvertently dropped? (b) How long was it falling?

Dec 7, 2015

$\left(a\right)$

$29.4 \text{m}$

$\left(b\right)$

$2.45 \text{s}$

#### Explanation:

$\left(a\right)$

${v}^{2} = {u}^{2} + 2 a s$

This becomes:

${24}^{2} = 0 + 2 \times 9.8 \times s$

$\therefore s = \frac{576}{2 \times 9.8} = 29.4 \text{m}$

$\left(b\right)$

$s = \frac{1}{2} \text{g} {t}^{2}$

:.t=sqrt((2s)/(g)

$\therefore t = \sqrt{\frac{2 \times 29.4}{9.8}} = 2.45 \text{s}$