Please tell me how to solve it?

#16t^2 enter image source here

1 Answer
Sep 3, 2017

(a) 8080 "ft/sec"ft/sec
(b) 160160 "ft/sec"ft/sec

Explanation:

Average speed is given by:

barv=(Deltax)/(Deltat)

Here, Deltax is the change in position, or s(5)-s(0) feet.
Deltat is 5-0 seconds.

barv=(s(5)-s(0))/(5-0) "ft/sec"

color(white)barv=(16*25-16*0)/5 "ft/sec"

color(white)barv=80 "ft/sec"

To find the instantaneous velocity at t=5, we need to differentiate s to find v.

v=(ds)/dt=d/dt16t^2=32t

Thus, at t=5:

v=32*5=160 "ft/sec"