Question

The acceleration due to the moon's gravity at its surface is less than what it is here on the surface of the earth. The computed value of 1.6 m/s2 is consistent with what the Apollo Program astronauts observed during their explorations there. Imagine an astronaut holding a piece of moon rock over the rim of a crater. At time zero the rock is 500 m above the crater floor and is tossed upward at 5.0 m/s. What will be the velocity of this rock 15 s after it was tossed upward?

Answer 1

g=1.6 m/s²
Upward motion
v=v₀-gt
v=0
t= v₀/g=5/1.6 =3.125 s
Downward motion
t₁=15-3.125 =11.875 m/s
v=gt₁=1.6•11.875=19 m/s