To calculate the force of gravity acting on an object, you can use the formula:
\[ F = m \cdot g \]
where \( F \) is the force, \( m \) is the mass, and \( g \) is the acceleration due to gravity.
On the Moon, the acceleration due to gravity is approximately \( 1.625 , \text{m/s}^2 \).
Given that the mass of the moon rock is \( 125 , \text{kg} \), we can substitute the values into the formula:
\[ F = 125 , \text{kg} \cdot 1.625 , \text{m/s}^2 \]
Now calculate \( F \):
\[ F = 125 \cdot 1.625 = 203.125 , \text{N} \]
Since this value does not exactly match any of the given options, we can approximate it:
The closest option to 203.125 N is B) 200 N.