Question

16. On the moon, Bob weighs 160 N while on earth Fred weighs 882 N Who has thegreater mass?

Answer 1

We are given the weight of two people, one on the moon and the other on earth. To determine the mass we will use the following formula:

$W=mg$

Where:

$\begin{gathered} W=\text{ weight,}\lbrack N\rbrack \\ m=\text{ mass,}\lbrack kg\rbrack \\ g=\text{ acceleration of gravity, }\lbrack\frac{m}{s^2}\rbrack \end{gathered}$

Now, we solve for the mass "m" by dividing both sides by "g":

$\frac{W}{g}=m$

Now, for the case of the moon we have that the acceleration of gravity is:

$g_{moon}=1.62\frac{m}{s^2}$

Plugging in the values:

$\frac{160N}{1.62\frac{m}{s^2}}=m$

Solving the operations:

$98.77kg=m$

Now, for the case of the earth we have:

$g_{\text{earth}}=9.8\frac{m}{s^2}$

Plugging in the values:

$\frac{882N}{9.8\frac{m}{s^2}}=m$

Solving the operations:

$90kg=m$

Therefore, the greater mass is the mass of Bob.