Questions from Modern Physics

Q: If the two ends of a rope in equilibrium are pulled with

If the two ends of a rope in equilibrium are pulled with forces of equal magnitude and opposite directions, why isn’t the total tension in the rope zero?

Q: You tie a brick to the end of a rope and whirl

You tie a brick to the end of a rope and whirl the brick around you in a horizontal circle. Describe the path of the brick after you suddenly let go of the rope.

Q: A large crate sits on the floor of a warehouse. Paul

A large crate sits on the floor of a warehouse. Paul and Bob apply constant horizontal forces to the crate. The force applied by Paul has magnitude 48.0 N and direction 61.0° south of west. How much w...

Q: Compared with the force her neck exerts on her head during the

Compared with the force her neck exerts on her head during the landing, the force her head exerts on her neck is (a) the same; (b) greater; (c) smaller; (d) greater during the first half of the landin...

Q: A large crate is suspended from the end of a vertical rope

A large crate is suspended from the end of a vertical rope. Is the tension in the rope greater when the crate is at rest or when it is moving upward at constant speed? If the crate is traveling upward...

Q: A man sits in a seat that is hanging from a rope

A man sits in a seat that is hanging from a rope. The rope passes over a pulley suspended from the ceiling, and the man holds the other end of the rope in his hands. What is the tension in the rope, a...

Q: “In general, the normal force is not equal to the

“In general, the normal force is not equal to the weight.” Give an example in which these two forces are equal in magnitude, and at least two examples in which they are not.

Q: The sign of many physical quantities depends on the choice of coordinates

The sign of many physical quantities depends on the choice of coordinates. For example, ay for free-fall motion can be negative or positive, depending on whether we choose upward or downward as positi...

Q: You drive a car up a steep hill at constant speed.

You drive a car up a steep hill at constant speed. Discuss all of the forces that act on the car. What pushes it up the hill?

Q: If there is a net nonzero force on a moving object,

If there is a net nonzero force on a moving object, can the total work done on the object be zero? Explain, using an example.