(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

My friend's little brother took some physics test a week or so ago, and he was asking about some of the questions that were on it. This was one of them:

There is a rod (uniform density, mass) which is balancing on the ground on its end (It basically looks like a flag pole). Someone comes along and kicks the bottom of it really quickly - describe what happens to the center of gravity (also the geometric center) of the rod.

2. Relevant equations

[tex]F_g = m_c*g[/tex]

[tex]\tau = F \times d[/tex]

3. The attempt at a solution

I figured that kicking the bottom of the rod would cause a torque around the center of gravity, so the rod would rotate. However, you also have gravity acting on the center of gravity, so the rod would fall downwards. Therefore, the center of gravity just moves straight down until it hits the floor.

Any thoughts/critiques/suggestions?

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

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: Center of gravity

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