Thursday, 21 December 2017

What is torque?

In our daily life we hear the term Torque but what is the definition and how it can be calculated we have to know it too. Torque is a general physics term, In simple terms, the definition of torque is a twisting or rotational force (It doesnt do any work by itself - simply say that it is the application of energy).
"Torque is the force that tends to turn or rotate objects about its axis or fulcrum or pivot". Image credits: https://www.mountztorque.com/sites/default/files/What-is-torque-image_0.jpg
When torque is applied on a body and moment occurs then we say that work (or stuff) happened. In simple way we can generate torue anytime by using a wrench. The best example for this is tightening a nut. While tightening a nut with a wrench, we use force or apply force on the handle. This force creates a torque on the nut and tends to turn the nut.
"To calculate the torque, we just multiply the force by the perpendicular distance from an axis (Fulcrum or Pivot) to the line of action of force (moment arm)"

In summary:
Torque = Force multiplied by Distance

Notice that units of Torque contains Force and Distance.
SI units are Newton-meter
N·m = (kg*m²)/s².
Imperial units (or) English units are  pound-inches or pound-feet Image Courtesy: Google
In the case of tightening a nut, if we used a wrench 0.2 meters of length, and we put 20 newtons of force on it, then we are generating 4 N-m of torque. If we use double the length i.e., 0.4 m length wrench, we only need to put 10 Newton of force on it to generate the same torque.

Some more types of Levers Image credits: https://lh3.googleusercontent.com/-GlLBr_-Xsfg