Question

The displacement (in metre) of a particle moving along x-axis is given by x= 18t + 5tsquare. Calculate :
(i) the instantaneous velocity at t = 2 s,
(ii) average velocity between t = 2 s, t = 3 s,
(iii) instantaneous acceleration.​

Answer 1

i) instantaneous velocity= ds /dt =18+10t

   at t=2 sec,

     ds/dt=38...so instantaneous velocity=38m/s

ii)displacement in 2 sec=56m

   displacement in 3 sec=99m

  dispacement that has taken place between 2 and 3 sec=99-56=43m

    so avg velocity=43m/s

iii)instantaneous acceleration=dv/dt=10m/s^2

Hope this helps u