Question

A horizontal rope is tied to a 20 kg box on frictionless ice.

Part A

What is the tension in the rope if the box is at rest?

Express your answer in newtons.

Part B

What is the tension in the rope if the box moves at a steady 6.0 m/s ?

Express your answer in newtons.

Part C

What is the tension in the rope if the box has vx = 6.0 m/s and ax = 5.0 m/s2

Express your answer in newtons

Answer 1

PART A:

If the box is at rest and there is no other force applied on the ice, the tension in the rope is zero.

Because there is no force and no frictional force in the horizontal direction.

PART B:

If the box is moving with a constant velocity, the acceleration is zero. So, again the force is zero in the horizontal direction.

So, again the tension in the rope is zero.

PART C:

Now there is an acceleration of 5 m/s^2. that means the rope is applying a force and that force is equal to