Answer:
The mass of the boulder remains constant, while its weight decreases with respect to the value of gravitational force on the moon.
Explanation:
The mass of the boulder = 15 kg
On the earth, its mass remains 15 kg. But its weight is;
weight = m x g
= 15 x 9.8
= 147 N
The boulder's weight on the earth is 147 N.
When transferred to the moon, the mass remains constant i.e 15 kg. But its weight decreases due to a change in the value of acceleration due to gravity on the moon. Thus, the boulder becomes lighter in weight.