Torque is the rotational equivalent of force. Torque is an important concept in physics and engineering. It is used in many different applications, such as opening doors, turning wrenches, and driving cars. It is a vector quantity that measures the tendency of a force to rotate an object about an axis. The torque vector is defined as the cross product of the force vector and the position vector from the axis of rotation to the point of application of the force. The SI unit of torque is the newton-meter (N⋅m). Other common units of torque include the pound-foot (lbf⋅ft) and the ounce-inch (ozf⋅in).
The formula for torque is:
τ = F × r
where:
- τ is the torque vector
- F is the force vector
- r is the position vector from the axis of rotation to the point of application of the force
Torque is a vector quantity, so it has both magnitude and direction. The direction of the torque vector is perpendicular to both the force vector and the position vector. The direction of the torque vector can be determined using the right-hand rule. Torque is a measure of the ability of a force to cause rotation. The greater the torque, the more likely it is that the object will rotate. The torque also depends on the distance between the axis of rotation and the point of application of the force. The farther away the force is applied, the greater the torque.
Examples of torque:
When you open a door, you are applying torque to the doorknob. The torque is equal to the force you apply to the doorknob multiplied by the distance between the doorknob and the hinges.
When you use a wrench to turn a nut, you are applying torque to the nut. The torque is equal to the force you apply to the wrench multiplied by the length of the wrench. The engine in a car produces a torque that turns the wheels. The amount of torque produced by the engine depends on the size and design of the engine.
Direction of Torque:
The direction of the torque vector is perpendicular to both the force vector and the position vector. It can be determined using the right-hand rule. To use the right-hand rule, imagine that you are holding the force vector in your right hand, with your fingers pointing in the direction of the force. If you curl your fingers in the direction of the position vector, your thumb will point in the direction of the torque vector.
For example, if you are pushing on a doorknob with your right hand, the force vector will be pointing in the direction of your fingers. The position vector will be pointing from the hinges of the door to the doorknob. The torque vector will be pointing in the direction that the door will rotate, which is perpendicular to the door and your hand.
Dimensional Formula Of Torque:
The dimensional formula of torque is M1 L2 T−2, where:
- M is the mass
- L is the length
- T is the time
The dimensional formula of torque can be derived from the formula for torque:
τ = F × r
where:
- τ is the torque
- F is the force
- r is the position vector
The dimensional formula of force is M1 L1 T−2, and the dimensional formula of the position vector is L. Therefore, the dimensional formula of torque is M1 L2 T−2.
In other words, torque is a vector quantity that has dimensions of mass, length squared, and time squared. The SI unit of torque is the newton-meter (N⋅m).