What is the average acceleration of the partide within the time interval 1 second to 3 seconds

Answer:A particle has zero velocity initially (i. e., at time

t=0

t=0

) and its acceleration at

t

t

seconds is

a (t) = 72t-4

t

3

a (t) = 72t-4t3

meters-per-second per second. During the time interval

[5,8]

[5,8]

seconds find the average acceleration and the average speed of the particle. I got the average acceleration by taking the integral and then plugging that into

f (8) - f (5) / 8-5

f (8) - f (5) / 8-5

but I have tried working through the average speed and I can't find the answer for that one.