The question describes a scenario in which three balls of equal mass are launched from a cannon on top of a 100m cliff at the same speed (50 m/s) but at different angles (0, 30, and 60 degrees). The question asks which of the following balls hits the ground with the greatest kinetic energy. The answer is that all of them hit the ground with the same kinetic energy. Their reasoning is that all the balls have the same initial and final PE and same initial KE, as they all start from the same height and end at the same height.(adsbygoogle = window.adsbygoogle || []).push({});

(PE + KE)_{final }= (PE + KE)_{initial}

I'm confused because intuitively this doesn't make sense to me. Even though they start at the same height and finish at the same height, the balls don't hit the ground with the same velocity, which should affect their final KE based on the equation KE = 1/2 mv^{2}. No?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: KE realated to translational motion

**Physics Forums | Science Articles, Homework Help, Discussion**