Suppose our experimenter repeats his experiment on a planet more massive than earth, where the acceleration due to gravity is g=30 m/s2. when he releases the ball from chin height without giving it a push, how will the ball's behavior differ from its behavior on earth? ignore friction and air resistance. (select all that apply.)

that speeds and heights are three times higher on the planet than on Earth

Explanation:

The physics equations are the same in all initial systems, which in the first approximation is fulfilled on that planet. On a planet with greater value of the acceleration of gravity what would change would be the value that we place in the acceleration of the body. Let's find the speeds and heights on this planet

                  Vfp = Vo - gp t

                   Yp = Vo t - ½ gp t2

How the body leaves rest

                  Vfp = - gp t

                  Yp = - ½ gp t2

                  Vfp = - 30 t

                   Yp = - ½ 30 t2

                   Yp = -15 t2

Let's write the same equations for Earth

                    Vf = - 9.8 t

                    Y = - ½ 9.8 t2

                    Y = -4.9 t2

By analyzing these two equations we can see that for the same time the speed and height that the body descends would be greater, we will compare the results between the Earth and the planet finding the relationship between them.

                      Vfp / Vf = -30t / (- 9.8t)

                      Vfp / Vf = 30 / 9.8 = 3

                      Vfp = 3 Vf

                      Yp / Y = -15t2 / (- 4.9t2) = 3

                       Yp = 3 Y

We can see that speeds and heights are three times higher on the planet than on Earth

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s