Dear friends, Please read our latest blog post for an important announcement about the website. ❤, The Socratic Team

A ball is thrown horizontally from a cliff at a speed of 15 m/s and strikes the ground 45 meters from the base of the cliff. How high was the cliff?

1 Answer
Write your answer here...
Start with a one sentence answer
Then teach the underlying concepts
Don't copy without citing sources


Write a one sentence answer...



Explain in detail...


I want someone to double check my answer

Describe your changes (optional) 200

Mark C. Share
Nov 19, 2017


Assuming air resistance is negligible, we can state that the ball flew for 3 seconds (#t = d/v#)


This then allows us to use a kinematic equation (SUVAT equation) to solve for the vertical distance travelled. Initial (vertical) velocity, called ‘u’ below is zero as the ball is thrown horizontally.

We’ll use #s = u.t + 1/2 a.t^2# knowing the acceleration to be 9.81 #m/s^2# (I guess the ball hits the earth, not another body!) and that u in the vertical direction is zero, we get #s = 1/2a.t^2#

#s = 1/2xx9.81(3^2)#

#s = 44.145# m

I’d quote this to 2 sig. figs., as the data in the question implies.

Was this helpful? Let the contributor know!