Think about galileos inclined plane experiments if a metal

Question

Think about Galileo's inclined plane experiments.

a) If a metal marble rolls 15 cm in the first unit of time, how farwill it roll in the third unit of time?

b) If the units of time were seconds, what is the speed of the ballafter the first unit of time? After the third unit?
What is the acceleration?

c) We did not derive Galileo's equations of motion. However, we maywant to verify that they are at least possible.

One quick check is that they should be dimensionally accurate.Confirm with the equations below:
Vf=V_o+at
d=(Vf²-Vo²)/2a
d=V_ot+1/2at²