Question

A skydiver leaps from a plane, and after a while is accelerating at 7.5 m/s2 downward. If the skydiver has a mass of 61 kg, find the force of air resistance acting on the skydiver.

Answer 1

on the skydiver are acting two forces, namely:
- the weight force \(W\)
- the resistance \(F\)
so we can write this formula:
\[\Large F = W - ma\]
where \(a=7.5\)
Using numeric data, we have:
\[\Large \begin{gathered}
F = W - ma = mg - ma = m\left( {g - a} \right) = \hfill \\
\hfill \\
= 61 \cdot \left( {9.81 - 7.5} \right) = ...newtons \hfill \\
\end{gathered} \]

Answer 2

of course, the air resistance \(F\) is directed downwards