Chapter SH, Problem 3.8APP

To determine

To Calculate: The net force on the person.

Answer to Problem 3.8APP

560 N

Explanation of Solution

Given:

Weight of the person, $w=686\text{N}$

Downward acceleration, $a=1.8{\text{m/s}}^{\text{2}}$

Formula Used:

From Newton’s second law of motion, the net force would be:

  ${\displaystyle \sum F=ma}$

Here, m is the mass and a is the acceleration.

Weight of an object can be obtained by:

  $w=mg$

Here, g is the acceleration due to gravity.

Calculations:

When the elevator accelerates downwards:

  $\begin{array}{l}ma=mg-N\\ N=mg-ma\\ N=686\text{N-}\left(\frac{686}{9.8}\right)\left(1.8\right)\\ N=560\text{N}\end{array}$

Conclusion:

Thus,the net force on the person is 560 N.