Torque vs Force: What's the Difference?

[burak_ilhan]

as you all now torque in rotational motion has similarity with force in translational motion. but torque has the same unit as energy.it seems to me that there is a problem. Any explanation you have? (please ssmt different than " they are defined that way!"

 

[krab]

In translational motion, work done (energy) is

$$E=\int Fdx$$

In the same manner, in rotational motion,

$$E=\int\tau d\theta$$

Since $$\inline{\theta}$$ is dimensionless, torque $$\inline{\tau}$$ has same units as energy. If it helps in keeping things apart, you can think of the units of torque as being say joules per radian.