Tension in a Flexible Cord

Tension is a force.

When a flexible cord pulls on an object, the cord is said to be under tension, and the force it exerts on the object is the tension F (T).


Two boxes , A and B , are connected by a cord. A person pulls horizontally on the box A with force F (p) = 40.0 N.

T (upper) = T (lower)

By the 2nd law and the fact that the system is at rest,

T (upper) = T(lower) = W