given:
s = f(t)
f(t) = 80t-6t^2
t=4
s = f(4) = 80*4-6*4^2=224
velocity= f'(t) =80-12t
velocity= f'(t) =80-12*4
velocity= f'(t) =32
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Speed is a scalar quantity that refers to "how fast an object is moving."
Velocity is a vector quantity that refers to "the rate at which an object changes its position." Imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position.
