Question

An astronaut uses a pendulum with a mass of 0.200 kg to measure the acceleration due to gravity on Planet X. He lifts the pendulum's mass a vertical height of 0.500 m and is able to determine that it gains 15.0 J of gravitational potential energy as it is lifted. Using this information, calculate the acceleration due to gravity (g) on Planet X. *

Answer 1

By the definition of the gravitational potential energy we have:

$$GPE=mgh,$$ $$g=\dfrac{GPE}{mh},$$ $$g=\dfrac{15.0\ J}{0.2\ kg\cdot0.5\ m}=150\ \dfrac{m}{s^2}.$$