Questions from College Physics

Q: A large barrel lies on its side. In order to roll

A large barrel lies on its side. In order to roll it across the floor, you apply a horizontal force, as shown in the figure. If the applied force points toward the axis of rotation, which runs down th...

Q: A cell membrane has a surface area of 1.1×

A cell membrane has a surface area of 1.1×10−7 m2, a dielectric constant of 5.2, and a thickness of 7.2 nm. The potential difference across the membrane is 70 mV. (a) What is the magnitude of the cha...

Q: A parallel plate capacitor has a charge of 0.020 µC

A parallel plate capacitor has a charge of 0.020 µC on each plate with a potential difference of 240 V. The parallel plates are separated by 0.40 mm of air. What energy is stored in this capacitor?

Q: Animals that can run fast always have thin legs. Their leg

Animals that can run fast always have thin legs. Their leg muscles are concentrated close to the hip joint; only tendons extend into the lower leg. Using the concept of rotational inertia, explain how...

Q: The bungee jumper of Example 6.4 made a jump into

The bungee jumper of Example 6.4 made a jump into the Gorge du Verdon in southern France from a platform 182 m above the bottom of the gorge. The jumper weighed 780 N and came within 68 m of the botto...

Q: An ideal solenoid has length I. If the windings are compressed

An ideal solenoid has length I. If the windings are compressed so that the length of the solenoid is reduced to 0.50ℓ, what happens to the inductance of the solenoid?

Q: Does a manometer (with one side open) measure absolute pressure

Does a manometer (with one side open) measure absolute pressure or gauge pressure? How about a barometer? A tire pressure gauge? A sphygmomanometer?

Q: Bernoulli’s equation applies only to steady flow. Yet Bernoulli’s equation allows

Bernoulli’s equation applies only to steady flow. Yet Bernoulli’s equation allows the fluid velocity at one point to be different than the velocity at another point. For the fluid velocity to change,...

Q: Before getting an oil change, it is a good idea to

Before getting an oil change, it is a good idea to drive a few miles to warm up the engine. Why?

Q: Your ears “pop” when you change altitude quickly—such

Your ears “pop” when you change altitude quickly—such as during takeoff or landing in an airplane, or during a drive in the mountains. Curiously, if you are a passenger in a high-speed train, your ear...