A ball rolling down an incline travels 6.0 cm in the first 0.25 seconds, and 24 cm in the first…

A ball rolling down an incline travels 6.0 cm in the first 0.25 seconds, and 24 cm in the first 0.50 seconds. Find: 

a)  The average speed for the first quarter second time interval 

b)  The average speed for the second quarter second time interval. 

c)  Find its acceleration.