Question

An object is hanging by a string from the ceiling of an elevator. The elevator is moving upward with a constant speed. What is the magnitude of the tension in the string?

Answer 1

Answer:

Equal to the weight of the object

Explanation:

There are two forces acting on the object hanging on the string:

- The tension in the string, T, acting upward

- The weight of the object, mg, acting downward

We can write Newton's second law as:

$T-mg=ma$

where a is the acceleration of the object.

Here we are told that the elevator is moving at constant speed: this means that the acceleration of the object is zero, therefore a = 0 and the equation becomes

$T=mg$

therefore, the tension in the string is equal to the weight of the object.