Question

A ball is launched from the ground with a horizontal speed of 30 m/s and a vertical speed of 30 m/s. When will the ball hit the ground again? A. 4 s B. 6 s C. 3 s D. 5 s

Answer 1

Answer:

B. 6 s

Explanation:

Given in the y direction:

Δy = 0 m

v₀ = 30 m/s

a = -10 m/s²

Find: t

Δy = v₀ t + ½ at²

0 m = (30 m/s) t + ½ (-10 m/s²) t²

0 = 30t − 5t²

0 = 5t (6 − t)

t = 6