average velocity and instantaneous velocity?

Question

The position of a small object is given by X=34+10t+2t^3, where t is in seconds and x in meters.

what is the average velocity of the object between 0 and 3.0s? at what time between 0 and 3.0s is the instantaneous velocity zero?

x is a function of t when graphed t=0 to t=3.0.

Answer 1

instantaneous velocity is
dX/dt=10+6*t^2

This is never zero for any value of t

did you pose the question correctly?

if x(t)=34+10t-2t^3
then v(t)=10-6*t^2
v(t)=0 when t= sqrt(10/6)
or t=1.3 seconds

j