How to Make Your Friends Feel Worse After Bragging About Cliff Jumping

We all have that friend who likes to exaggerate a bit too much. Conversations with this friend are the worst when they just came back from a tropical vacation. More likely than not, your friend had the opportunity to jump off some rocks into the ocean. When they are explaining how awesome their cliff jump was, they show you the video (Just to make sure you are grasping how amazing your friend is). The height of the cliff that your friend tells you seems much higher, compared to the sick GoPro video of the jump. Your friend tells you the jump is 100 feet from the water, but cliff jumps are usually in the area of 25-45 feet. Since you are very annoyed from your friend explaining how their jump was so difficult, you whip out your phone calculator and do some physics.

The equation to find the height of a cliff jump in feet is quite easy. After simplifying Newton's second equation of motion, finding the height of a cliff can be done by squaring the time it took for a person to hit the water and multiplying it by 16.

d = cliff height
t = time it takes for a person to jump then hit the water

d = 16 x t²

For Example:

Time from jump to water is one second- 

d = 16 x 1²

d = 16 x 1

d = 16 feet         (The cliff was 16 feet high)


Now that you watched the video of your "sick" friend and timed their jump, you can correct them on facts about their vacation. Here is a video of Mark Rober, a NASA Engineer, on this subject.

Works Cited

Mailonline, Kelly Mclaughlin For. "Moo-dunnit? Mystery as a Herd of 12 Cows Jumps to Its Death off of a 50-metre Swiss Cliff." Daily Mail Online. Associated Newspapers, 05 June 2017. Web.

Measure Height with a Watch! Cliff Jump Science. Dir. Mark Rober. YouTube. YouTube, 05 Aug. 2014. Web.

Rose, Brent. "The Easy Way to Know the Height of the Cliff You're Jumping Off." Gizmodo. Gizmodo.com, 05 Aug. 2014. Web.