Questions from Modern Physics

Q: The human heart is a powerful and extremely reliable pump. Each

The human heart is a powerful and extremely reliable pump. Each day it takes in and discharges about 7500 L of blood. Assume that the work done by the heart is equal to the work required to lift this...

Q: Figure P6.90 shows the results of measuring the force F

Figure P6.90 shows the results of measuring the force F exerted on both ends of a rubber band to stretch it a distance x from its unstretched position. (Source: www.sciencebuddies.org) The data points...

Q: In a physics lab experiment, one end of a horizontal spring

In a physics lab experiment, one end of a horizontal spring that obeys Hooke’s law is attached to a wall. The spring is compressed 0.400 m, and a block with mass 0.300 kg is attached...

Q: For a physics lab experiment, four classmates run up the stairs

For a physics lab experiment, four classmates run up the stairs from the basement to the top floor of their physics building—a vertical distance of 16.0 m. The classmates and their m...

Q: Can a body be in equilibrium when only one force acts on

Can a body be in equilibrium when only one force acts on it? Explain.

Q: An elevator is hoisted by its cables at constant speed. Is

An elevator is hoisted by its cables at constant speed. Is the total work done on the elevator positive, negative, or zero? Explain.

Q: A clothesline hangs between two poles. No matter how tightly the

A clothesline hangs between two poles. No matter how tightly the line is stretched, it sags a little at the center. Explain why.

Q: If it takes total work W to give an object a speed

If it takes total work W to give an object a speed v and kinetic energy K, starting from rest, what will be the object’s speed (in terms of v) and kinetic energy (in terms of K) if we do twice as much...

Q: For medical reasons, astronauts in outer space must determine their body

For medical reasons, astronauts in outer space must determine their body mass at regular intervals. Devise a scheme for measuring body mass in an apparently weightless environment.

Q: A rope tied to a body is pulled, causing the body

A rope tied to a body is pulled, causing the body to accelerate. But according to Newton’s third law, the body pulls back on the rope with a force of equal magnitude and opposite direction. Is the tot...