Question

a ball rolls horizontally off a cliff at a speed of 30m/s. it takes about two seconds for the ball to hit the ground. calculate the height of the cliff and the horizontal distance travelled by the ball. ​

Answer 1

(a) The height of the cliff is 19.6 m

(b) The horizontal distance travelled by the ball is 60 m

Step-by-step explanation:

Given;

initial horizontal velocity of the ball, u = 30 m/s

initial vertical velocity of the ball, v = 0

time taken for the ball to hit the ground, t = 2 s

(a) height of the cliff

h = vt + ¹/₂gt²

h = 0 + ¹/₂gt²

h = ¹/₂gt²

h = ¹/₂(9.8)(2)²

h = 19.6 m

(b) horizontal distance traveled by the ball = Range

Range = ut

Range = 30 (2)

Range = 60 m