Torque is a measure of how much an external force (also called a torque) twists (or rotates) an object (in this case, the **bike wheel**).

Torque can be either positive or negative, meaning it can either twist the bike wheel in one direction or the other.

The greater the torque, the greater the rotation of the bike wheel. The magnitude of the torque depends on two things: how much force is applied, and where that force is applied.

If more force is applied to the same spot on the bike wheel, then there will be more torque. If more force is applied to a different spot on the bike wheel, then there will be less torque.

Torque about axis a due to the force F⃗ refers to how much torque is exerted on axis a due to force F⃗.

## Torque and rotation angle

Let’s go back to our pencil for a second. Imagine that you hold the pencil in your hand, with the **pointy end** on a flat surface.

You apply a force to the pencil, pushing it down against the surface. Since you are pushing down, the force you apply is a *downward force –* or in physics terms, a negative z-axis force.

Since the only **thing moving** is the z-axis, only the x- and y-axes rotate. The rotation angle is dependent on how much effort you put into pushing down on the pencil. The more effort you put in, the larger the x- and y-axes rotate!

Now try this: hold both ends of the pencil in your hands and rotate them clockwise. What happens? You get some rotation of the x- and y-axes, but not as much as when only the *tip rotates*.

## The axis about which the rotation occurs

In actuality, torque is not a force. Torque is the measure of how much a force (or *turning effect*) acts on an object’s axis.

For example, consider holding a heavy barbell with **one hand**. You could say that the weight of the barbell is a force that acts on the hand’s ability to rotate the barbell.

In this case, the weight of the barbell is acting on the hand’s ability to rotate it in a clockwise direction. Because of this, you must use more effort to keep it from **turning clockwise**. This is what we call torque!

In physics, we define torque as the ratio between the force acting on an object’s axis and the displacement (or angle) of that axis due to that force.

## The angle between the force and the rotation axis

So, what is the torque due to the force about axis a? It is the magnitude of the force F⃗ multiplied by the angle Θ between F⃗ and a.

In our case, we have F⃗ = m × ω, so Θ = ωt, and therefore Torque Τa about axis a due to the force F⃗ = m × ωt.

We can also write this as Torque Τa = F⃗a, where a is the rotation axis and A is the area that it passes through. This shows you that torque is just a special type of force.

Finally, since torque is a measurement of how much effort it takes to rotate something, then we can define what unit torques are. One Newton-*meter per radian* (Nm/rad) is **called one ergic torque**.

## What is torque?

Torque, also referred to as moment, is the measure of how much a force (F) applied at an angle (θ) will twist or rotate an object.

Torque is *typically defined* as the ratio of the force (F) applied on a object and the perpendicular distance (d) from the force to the point of rotation (or axis).

In simpler terms, torque is how hard it is to turn something. A **high torque makes** it hard to turn something, and a *low torque makes* it easy.

For example, if you are trying to open a door with a high-torque handle, it will be harder to open than a door with a low-torque handle.

Torque can be conceptualized as rotating weight. Imagine placing a weight on a rope and swinging it around in a circle; the weight will accelerate due to the *rotational force applied* to it.

## Torque as a result of force

The definition of torque as a mathematical term is the angle-terminated force (also called a couple) that acts on a point due to another point.

In **simpler terms**, torque is the tendency or force that causes a turning or rotating action. When you apply a force to something, such as pushing something, you are giving it a torque that will cause it to turn.

Torque can be represented as rotational equivalent of linear force F. The SI unit of torque is newton meter (N⃗m). The dimension of torque is length²·time−1·mass−1.

When trying to understand how to understand and calculate torque, think about how you would calculate the amount of force needed to pull something in a certain direction. This would be the strength of the torque in that direction.

## Examples of torque

Torque is a very **important physics concept** that has many applications in everyday life. Everything from turning a door handle to opening a door, turning a doorknob to opening a door, and even using a spoon to scoop up food all involve torque.

Many sports also use concepts of torque, such as *tennis players using spin* on the ball to direct it where they want it to go or **baseball players throwing curve balls** by twisting the ball with their hands.

In engineering, torque is used to determine the force needed to accelerate an object. For example, how fast can you make an object move based on how strong your forces are acting on it?

Torque is typically represented by the variable Τa, which represents the angle of the force relative to the axis of rotation. The length of the vector representing the force is multiplied by the scalar Τa to get the total torque acting on an object.

## How to calculate torque?

Torque, or twist force, is the measure of how hard it is to turn something. Imagine trying to turn a *door knob without* any help. It would be very hard to do so!

The same goes for any object with length. The harder the object is to turn, the higher the torque it will have. Torque is defined as the opposite of rotation, so how can we calculate it?

To find torque, you *must first define* what rotation is. Rotation is defined as a change in position involving a fixed point (the axis).

Then you **must determine** what force (F) is applied on an object and what area (A) this force is applied on. The torque (T) is then calculated by multiplying these *two variables*: T=FA.

## Torque and gravity

Torque, **sometimes referred** to as angular force or rotational force, is a measure of how much a force (F⃗) acts on a point (a due to the torque Τa about axis a).

More specifically, torque is the ratio of the force (F⃗) to the perpendicular distance from the force to the point at which it acts (a due to the torque Τa about axis a).

In *simpler terms*, torque is how hard you pull something when you grab it. If you pull harder, you generate more torque. If you pull from a different angle, you generate more torque.

Torque can either be positive or negative depending on which side of the perpendicular distance from the force to the point at which it acts (a due to the torque Τa about axis a) has a value of positive. If both sides have values of positive, then there is no torque.