Question

An astronaut holds a rock 100m above the surface of Planet XX. The rock is then thrown upward with a speed of 15m/s, as shown in the figure. The rock reaches the ground 10s after it is thrown. The atmosphere of Planet XX has a negligible effect on the rock when it is in free fall. Determine the acceleration due to gravity of the rock when it is on Planet XX.

Answer 1

Answer:

Explanation:

Using the equation of motion to get the acceleration due to gravoty of the rock on the planet.

S = ut+ 1/2at² where;

S is the distance of the rock above the surface of the planet = 100m

u is the initial velocity = 15m/s

a is the acceleration due to gravity

t is the time taken by the rock to reach the ground = 10s

Since the rock is thrown upward the acceleration due to gravity will be negative i.e a= -g

The equation becomes S = ut- 1/2gt²

Substituting the given value to get the time t

100 = 15(10)- 1/2g(10)²

100 = 150-50g

100-150 = -50g

-50 = -50g

g = -50/-50

g = 1m/s²

Hence the acceleration due to gravity of the rock when it is on Planet XX is 1m/s²