Why is the SI unit of torque N m and not Joule?

Units are defined for “magnitude of a vector”, which by itself is a scalar. So, the reason you can’t use Joules for torque is because there is no consistent way of converting Newton-meters to Joules and vice versa.

What is the correct unit for torque?

Newton-meter
The SI unit for torque is the Newton-meter or kgm2sec-2. How we have come to this? If we look at the formula Torque = Force X Distance. While distance is measured in meters and force is measured in newton so torque is measured in newton ⋅ meter.

What is N m in torque?

Torque is measured in Newton metres (Nm) or you might see the imperial measurement of lb-ft (pounds-feet). If you want to calculate the conversion for yourself, 1 Nm is equivalent to 0.738 lb/ft.

Why unit of torque is joule?

The quantity torque (or moment of force) may be thought of as the cross product of force and distance and the SI unit for torque is Newton metre, N m (m2 kg s-2). Even though N m is the same as Joule, torque is not work or energy and hence torque should only be expressed in newton metres and not in Joules (J).

Is torque equal to work?

Work is a scalar and torque is a vector. The angular equivalent of work = force*displacement is: work = torque*angular displacement where angular displacement is measured in radians, which is dimensionless, so the unit for torque must necessarily have the same dimension as the unit for work.

Do work and torque have the same units?

Torque and work can not be interchanged because they do not represent the same thing. 1 Joule is the amount of energy required to move an object against a force of 1 N by 1 m. 1 Nm of torque, on the other hand, is the torque obtained if you apply a force of 1 N att a force arm of 1 m.

How does torque relate to energy?

The energy you are referring to is the energy required to move a body through a distance, and is given by force times distance along the direction of motion, while torque is force times a perpendicular distance, which means, by definition, there is no component of that force along that direction.