We already learned about the normal force - when you push on a surface it pushes you back. But what if you pull on something? What if you tied a rope to a pole and pulled on the rope? Something similar happens - the rope will exert an equal and opposite force on you. This is what we call tension.
Tension is a force that exists within objects when they're pulled, and for most physics classes we usually apply it to long, thin objects like ropes, strings, wires, cables, etc. If you attach a rope to an object and pull on it, the rope will exert a force on the object in the same direction as the rope itself. We say that the "tension in a length of rope" is equal to the tension force at both ends of the length of rope.
Like a normal force, a tension force exerted on an object is not a new "type" of force. The tension force from a rope is just a contact force that pulls on the object that the rope is attached to. We could think of a tension force like a spring force where the rope is a spring with an infinitely large spring constant because the rope doesn't change length. There are no new equations to learn, only interesting new scenarios that involve forces and motion in different directions.
The cool thing about a tension force is that it can change directions without changing magnitude because a rope is flexible. We'll learn about pulley systems where a rope bends around a pulley and changes the direction of a tension force (these are sometimes called Atwood's machines).
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- Tension
- Pulley Systems
We already learned about the normal force - when you push on a surface it pushes you back. But what if you pull on something? What if you tied a rope to a pole and pulled on the rope? Something similar happens - the rope will exert an equal and opposite force on you. This is what we call tension.
Tension is a force that exists within objects when they're pulled, and for most physics classes we usually apply it to long, thin objects like ropes, strings, wires, cables, etc. If you attach a rope to an object and pull on it, the rope will exert a force on the object in the same direction as the rope itself. We say that the "tension in a length of rope" is equal to the tension force at both ends of the length of rope.
Like a normal force, a tension force exerted on an object is not a new "type" of force. The tension force from a rope is just a contact force that pulls on the object that the rope is attached to. We could think of a tension force like a spring force where the rope is a spring with an infinitely large spring constant because the rope doesn't change length. There are no new equations to learn, only interesting new scenarios that involve forces and motion in different directions.
The cool thing about a tension force is that it can change directions without changing magnitude because a rope is flexible. We'll learn about pulley systems where a rope bends around a pulley and changes the direction of a tension force (these are sometimes called Atwood's machines).
1. Tension
2. Pulley Systems
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