Chapter 1, Problem 1.1P

A person weighs 30 lb on the moon, where $g=5.32{\text{ft/s}}^{\text{2}}.$ Determine (a) the mass of the person; and (b) the weight of the person on earth.

To determine

(a)

The mass of the person.

Answer to Problem 1.1P

The mass of the person is 5.64 slug.

Explanation of Solution

The person weighs 30 lb on the moon, where $g=5.32{\text{ft/s}}^2$.

Calculation:

Weight of one unit of mass is:

  $\begin{array}{l}W=mg\\ \Rightarrow m=\frac{W}{g}=\frac{30}{5.32}\\ =5.64\text{slug}\end{array}$

Conclusion:

The mass of the person is calculated using one unit of mass and then the ratio is calculated.

To determine

(b)

The weight of a person on earth.

Answer to Problem 1.1P

The weight of a person on earth is 181.61 lb.

Explanation of Solution

The mass of the person is 5.64 slug.

Calculation:

Weight of one unit of mass is,

  $\begin{array}{l}W=mg\\ \Rightarrow W=5.64\times 32.2\\ =181.61\text{lb}\end{array}$

Conclusion:

The weight of the person on earth has calculated using one unit of mass and then multiplied with the mass of a person.