Question

Neil Armstrong dropped a hammer on the moon. If it took 4 seconds to fall and the final speed was 8 ms, what is theacceleration due to gravity on the moon?

Answer 1

ANSWER

$g=2\text{ m/s}^{2}$

EXPLANATION

We want to find the acceleration due to gravity on the moon.

To do this, we have to apply one of the equations of motion for a body falling freely under gravity:

$v=u+gt$

where u = initial velocity

v = final velocity

g = acceleration due to gravity

t = time taken

Neil Armstrong dropped the hammer, so its initial velocity is 0 m/s:

$\begin{gathered} u=0\text{ m/s} \\ v=8\text{ m/s} \\ t=4\text{ s} \end{gathered}$

We have to solve for g:

$\begin{gathered} 8=0+g\cdot4 \\ \Rightarrow4g=8 \\ g=\frac{8}{4} \\ g=2\text{ m/s}^{2} \end{gathered}$

That is the acceleration due to gravity on the moon.