Question

It takes 30 seconds for a pumpkin to roll 25 meters from rest after it is pushed withforce of 12 Newtons. What is the mass of the pumpkin?

Answer 1

The velocity of pumpkin can be given as,

$v=\frac{d}{t}$

Plug in the known values,

$\begin{gathered} v=\frac{25\text{ m}}{30\text{ s}} \\ =0.833\text{ m/s} \end{gathered}$

The final velocity of pumpkin can be expressed as,

$v=u+at$

Substitute the known values,

$\begin{gathered} 0.833\text{ m/s=0 m/s+a(30 s)} \\ a=\frac{0.833\text{ m/s}}{30\text{ s}} \\ \approx0.028m/s^2 \end{gathered}$

The mass of pumpkin can be given as,

$m=\frac{F}{a}$

Plug in the known values,

$\begin{gathered} m=\frac{12\text{ N}}{0.028m/s^2}(\frac{1kgm/s^2}{1\text{ N}}) \\ \approx428.6\text{ kg} \end{gathered}$

Thus, the mass of pumpking is 428.6 kg.