Question

the position of an object moving along with x axis is given by x=a+bt2 where a=10m ,b=2ms and t is measured in second. What is its velocity at t=0s and t=3.0s .what is the average velocity between t =2.0s and t=4.0s ?

Answer 1

a) Differentiating x=a+bt2

             v=2bt

Now substituting

           =2*2*t

when t=0  

     2*2*0=0m/s

when t=3

     2*2*3=12m/s

b)when t=2.0s

    velocity=2*2*2=8m/s

  when t=4.0s

    velocity=2*2*4=16m/s

Now average velocity=(8+16)/2=12m/s