Physics – 1.2 Motion | e-Consult

We can use the following equation of motion: d = v_it + (1/2)at², where:

• d = distance (20m)
• v_i = initial velocity (0 m/s, since the ball is dropped)
• a = acceleration due to free fall (9.8 m/s²)
• t = time (what we need to find)

Substituting the values: 20 = 0*t + (1/2)*9.8*t²

20 = 4.9t²

t² = 20 / 4.9

t² ≈ 4.08

t ≈ √4.08 ≈ 2.02 seconds

Therefore, it takes approximately 2.02 seconds for the ball to reach the ground.