# Static Equilibrium

Do we need to know this for the test, and if so can you briefly go over it and how to do it?

Static equilibrium is a fancy way of saying that there is zero net force, zero net torque, and it’s not moving. So yep, it’s fair game for the test.

Any time you have done a “sum of the forces” or “sum of the torques” problem, and you set it equal to zero, you’ve done a static equilibrium problem.

ah that makes sense, i just havent done much with torque T~T

Good news, if you are A-ok at summing forces, it’s basically exactly the same for torque!

For Newton’s 2nd law, \sum F = ma, there is the rotational equivalent, \sum \tau = I\alpha. Where forces are either + or - for right or left, torques are + or - for clockwise or counterclockwise. It’s a little trickier because you have to actually calculate the torques, but if you remember that \tau = R \times F you’ll be A-ok!

that makes sense, thank you!

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