Answer:
The time taken before the phone hits the ground is 1.4 s.
Explanation:
Given;
height of the rock wall, h = 10 m
speed of the climber, v = 0.25 m/s
The time taken before the phone hits the ground is given;
h = ut + ¹/₂gt²
10 = 0.25t + ¹/₂(9.8)t²
20 = 0.5t + 9.8t²
9.8t² + 0.5t - 20 = 0
solving this quadratic equation;
t = 1.4 s
Therefore, the time taken before the phone hits the ground is 1.4 s.
