Question

If a ball with an original velocity of zero is dropped from a tall structure and it takes 7 seconds to hit the ground, what velocity does the ball have when it reaches the ground? A. 34.3 m/s B. 68.6 m/s C. 156.8 m/s D. 240.1 m/s

Answer 1

The velocity of the ball when it reaches the ground is equal to B. 68.6 m/s. This value was obtained from the formula Vf = Vi + at. Vf is the final velocity. Vi is the initial velocity. The acceleration is "a", while the time of travel is "t". The solution is:

Vf = Vi + at
Vf = 0 + (-9.8 m/s^2) (7 s)
Vf = -68.6 m/s

The negative sign denotes the direction of the ball.