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A soccer ball is released from rest at the top of a grassy incline. After 6.3 seconds, the ball travels 51 meters. One second later, the ball reaches the bottom of the incline.

a) What was the ball's acceleration? (Assume that the acceleration was constant.)

b) How long was the incline?

a)

at rest t=0 and yi=0

at t=6.3 yf=51 m

yf-yi= vi(t)+1/2(a)(t)^2

51m=0(6.3)+1/2(a)(6.3 s)^2

[(51m)(2)]/39.69s^2=a=2.57 m/s^2

b)

a(constant)=2.57m/s^2

t(final)=7.3s

deltay=vi(7.3s)+1/2(a)(t)^2

deltay=0+1/2(2.57m/s^2)(7.3s)^2

deltay=68.5m