Introduction to tension | Forces and Newton's laws of motion | Physics | Khan Academy

TL;DR

Tension is the force within or applied by a string or wire that counteracts the force of gravity, keeping an object stationary.

Transcript

I will now introduce you to the concept of tension. So tension is really just the force that exists either within or applied by a string or wire. It's usually lifting something or pulling on something. So let's say I had a weight. Let's say I have a weight here. And let's say it's 100 Newtons. And it's suspended from this wire, which is right here.... Read More

Key Insights

• 🛜 Tension is the force within or applied by a string or wire that opposes gravity and keeps an object stationary.
• 🪐 When an object is stationary, the net force on it is zero, meaning the force of tension must balance out the force of gravity.
• ❣️ Tension can be calculated using trigonometry by breaking down the force into its x and y components and using the angle between the string and a reference direction.

Questions & Answers

Q: What is tension in physics?

Tension refers to the force within or applied by a string or wire that opposes gravity and keeps an object stationary. It is essential in maintaining equilibrium and preventing acceleration.

Q: How does tension keep an object stationary?

When a weight is suspended from a string or wire, tension in the string provides an upward force that exactly offsets the force of gravity. This results in a net force of zero, keeping the object stationary.

Q: How is tension calculated?

Tension can be calculated using trigonometry. By breaking down the tension force into its x and y components, the angle between the string and a reference direction can be used to determine the force's magnitude.

Q: Why is tension important in engineering?

Tension is crucial in engineering when designing structures like bridges or cables. Knowing the tension a wire or string can support is essential for ensuring the stability and safety of the structure.

Summary & Key Takeaways

• Tension is the force within a string or wire that opposes the force of gravity and keeps an object stationary.

• When an object is stationary, the net force on it is zero, meaning the force of tension must balance out the force of gravity.

• The tension in a string can be calculated using trigonometry and the known angle between the string and a reference direction.