Question

On Planet Y, which has no air, a dropped object falls 9 m in 3 seconds. What is g, the acceleration due to gravity, on that planet?

9.8 m/s2
3 m/s2
2 m/s2

Answer 1

Answer:

a = 2 m/s^2

which agrees with the third answer option provided.

Explanation:

Recall the kinematic formula for displacement under the action of a constant acceleration "a":

yf - yi = 1/2 a  t^2

using the information provided this equation becomes:

9 = 1/2 a (3)^2

solve for a:

9 * 2 / 9 = a

then a = 2 m/s^2

which agrees with the third answer option provided.