Question

The position of a particle moving along the x-axis is given by x= 10t - 2t2. Then the time (t) at which it will momently come to rest is?

Answer 1

x = 10t - 2t^2
Differentiate with dt
dx/dt = 10 - 4t
v = 10 - 4t
If v = 0
0 = 10 - 4t
t = 2.5 seconds

It will momentarily comes to rest after 2.5 seconds from its start.