
Fernando G. answered 01/05/20
Notre Dame Grad specializing in chemistry, physics, math, theology
Velocity, measured in meters per second, is the rate of change of position (it tells us how much the position of the ball changes in a given time). Determining the derivative of a function is the same as determining the rate of change of the function.
So to get the velocity after 3 seconds, first get the derivative s ' (t).
s(t) = 4.9t^2+550
Use the product rule to derive:
s'(t) = (2)(4.9)t + 0
This simplifies to s'(t) = 9.8t
Since you're solving for the velocity after 3 seconds, plug in t=3:
s'(t) = 9.8 * 3 = 29.4 m/s