What is Tension in Physics?


Tension is a common force prevalent in the everyday experience of life. Tension is commonly experienced in applications where either a rope or a ropelike object is used. 

Defining Tension

In Physics, tension is defined as a force that is transmitted through a rope, cable or wire when it is pulled tight by forces acting from opposite ends. Tension is equal to the product of the mass of the object and the gravitational acceleration for suspended objects that are in equilibrium. Mathematically, tension definition is represented as follows:

T = mg


where T is the tension

m is the mass of the object

g is the gravitational acceleration (m/s2)

One of the important points to note about tension is that it is only a pulling force and not a pushing force. Trying to push the rope would cause the rope to go slack and lose the tension that allowed it to pull in the first place.

Some Commonly Asked Questions on Tension

What is the importance of Tension?

Tension is an intermolecular force that exists inside a rope, string or any kind of elastic materials. The purpose of the tension is to maintain the integrity of the system.

Does Tension depend on the length of the string?

The length of the string does not affect the tension.

Is tension a contact force?

Yes, tension is a contact force.

How can we find the direction of tension?

Tension always points away from the mass in the direction of the string/rope. In case of the hanging mass, the string pulls it upwards, so the string/rope exerts an upper force on the mass and the tension will be in the upper side.

What is the difference between stress and tension?

Stress is the internal distribution of force per unit area (pressure) within a body reacting to applied forces which causes strain or deformation while tension is a condition of being held in a state between two or more forces, which are acting in opposition to each other.

This was a brief summary of the tension force covering most of its nuances. Another closely related interesting topic in physics is stress. Stress is defined as the force per unit area. Stress causes the deformation of the body.  When a body is deformed, the body has a tendency to resist the deformation. This resistance can be quantified by the modulus of elasticity. Learn stress and many more topics in Physics in an interesting manner with the help of enticing animation and videos like never before only @ BYJU’S.