A particle moves with a displacement function s=20t-5t².Calculate the time taken for the particle to come to rest

Answer 1

If you want to find when the particle comes to rest, you want to know when its velocity equals zero.

To find velocity, take the derivative of the displacement function with respect to time:

ds/dt = v(t) = 20 - 10t

You want to know at what time is velocity zero so make it zero and solve for "t":

0 = 20 - 10t

t = 2

So, assuming "t" is measure in seconds, the particle comes to rest in 2 seconds