A torque is a force. Specifically, it's a force applied that can create a rotating motion.
A common example is the seesaw. Your applied force makes the seesaw rise and fall. The middle of the seesaw is called the fulcrum.
In class, we use torques to figure out people's weight in pounds.
We take a known weight person and put them at a certain distance from the fulcrum. We then take our unknown person and measure their distance from the fulcrum once the board balances.
WORKS EVERY TIME! (to within a pound or two)
In this picture, Josh was our known weight.
Everyone who already knew their weight agreed that our method is accurate.
The math
torquejosh=torqueira
FrsinQjosh=FrsinQira
mgrjosh=mgrira
mrjosh=mrira
So, all we had to do was plug in Josh's mass and distance,
then maesure the distance out to Ira.
That gave us 3 out of 4 variables... so we just solved
for Ira's mass (in pounds).
(Note: since the "m" cancels out,
we can use any unit we wish, including pounds, Kg, etc.)
If you know physics, please don't
harass me about using Newtons here.