Question

If Thor throws his axe horizontally at a velocity of 50 m/s at and a height of 20 m, how long does it take before it hits the ground? (gravity is 9.8 m/s^2)

Answer 1

The time taken before the axe hits the ground is 0.385 s.

Step-by-step explanation:

Given;

initial velocity, u = 50 m/s

height above ground, h = 20 m

To determine the time taken before the axe hits the ground, apply the following kinematic equation;

h = ut + ¹/₂gt²

20 = 50t + ¹/₂(9.8)t²

20 = 50t + 4.9t²

4.9t² + 50t - 20 = 0

Solve this quadratic equation;

a = 4.9, b = 50, c = -20

t = 0.385 s

Therefore, the time taken before the axe hits the ground is 0.385 s.