torque and force

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

[tex]E=\int Fdx[/tex]

In the same manner, in rotational motion,

[tex]E=\int\tau d\theta[/tex]

Since [tex]\inline{\theta}[/tex] is dimensionless, torque [tex]\inline{\tau}[/tex] 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.