Question

A projectile is thrown upward off a 130ft cliff at a velocity of 15ft/second. How long before it reaches a height of 25ft?

Answer 1

Answer:

The time taken for the projectile to reach the given height is 1.2 s.

Step-by-step explanation:

Given;

height of travel, h = 25 ft

initial velocity of the projectile, u = 15 ft/s

The time taken for the projectile to travel a height of 25 ft is given by the following kinematic equation;

h = ut + ¹/₂gt²

25 = 15t + ¹/₂(9.8)t²

25 = 15t + 4.9t²

4.9t² + 15t - 25 = 0

solving the quadratic equation, we will have the following solution of t;

t = 1.2 s

Therefore, the time taken for the projectile to reach the given height is 1.2 s.