Question

A brick is dropped from a high scaffold. What is it's velocity after 4.0s?

Answer 1

39.2 m/s

Step-by-step explanation:

We use the formula for velocity under the acceleration due to gravity, and understanding the the dropped brick was not imparted initial velocity.

vf = vi + g * t

using g = 9.8 m/s^2 and t= 4 seconds, we get

vf = 0 + 9.8 * 4 = 39.2 m/s