Chapter 3.2, Problem 14PP

To determine

The net force on the sky diver.

Answer to Problem 14PP

The net force on the sky diver is $500\text{}\text{N}\left(\text{down}\right)$

Explanation of Solution

Given info:

Constant velocity, $g=10\text{m}/\text{s}$ downward

Formula used:

Write the expression to calculate the net force.

  $F_{net}=W-AR$

Here,

• $W$ is the weight.
• $AR$ is the air resistance force.

Calculation:

Substitute the given values in the above equation.

Suppose that you have a mass of $50\text{kg}$ . Your weight, then is

  $\begin{array}{c}w=mg\\ =\left(50\text{kg}\right)\left(10\text{m}/\text{s}\right)\\ =500\text{N}\end{array}$

The magnitude of the vertical velocity is essentially zero.Since your weight and the air resistance force pull you in opposite directions, the net force on you equals your weight − air resistance.

  $\begin{array}{c}{F}_{net}=W-AR\\ =500\text{N}-0\text{N}\\ =500\text{N}\left(\text{down}\right)\end{array}$

Conclusion:

Hence, the net force on the sky diver is $500\text{}\text{N}\left(\text{down}\right)$ .