This is my first year at studying physics and I understand th econcepts however I am having trouble applying these concepts to "problem questions". This is a question I urgently need help with:(adsbygoogle = window.adsbygoogle || []).push({});

Lice, Bob, Charlie & Daniel are standing on the edge of a canyon which is 100m deep & 20m wide. On the opposite side of the canyon, there is a 10m high cave, 15m below the top of the cliff. They want to see who can throw a rock horizontally & get it into the cave. They each throw the rock with the following initial velocities: Alice 5m/s, Bob 10m/s, Cgarlie 15m/s, Daniel 20m/s. Whos rock makes it into the cave?

I know I need to find the time it takes for a rock to be thrown n hit the top of the cave, and for the bottom. Then calculate the time it takes each person the throw there rock and hit the opposing wall. Whoevers is inbetween the top of cave and bottom of cave times, is the person who will get there rock into the cave. I also know I must somewhere use the displacement rule...I have no idea how i should begin, what rules are needed, and how to complete such a difficult question! Help would be greatly appreciated

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

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

# Homework Help: Projectile Motion

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