Question

The displacement s of an object is given as a function of time t s=5t^2+9t. Calculate the instaneous velocity of object at t=0

Answer 1

S = 5t^2 + 9t
Differentiate with dt
dS/dt = (5t^2 + 9t)/dt
v = 10t + 9
At t = 0
v = 9

Velocity at t = 0 is 9

Answer 2

s=5t^2+9t

for instaneous velocity ,
we have to differentiate displacement with respect to time,

ds/dt=10t+9

now at time =0

velocity=9 meter per second