Questions from College Physics

Q: A room in which the air temperature is held constant may feel

A room in which the air temperature is held constant may feel warm in the summer but cool in the winter. Explain. [Hint: The walls are not necessarily at the same temperature as the air.]

Q: What is the velocity of the scattered electron in Problem 26?

What is the velocity of the scattered electron in Problem 26?

Q: A man with a mass of 70 kg stands on one foot

A man with a mass of 70 kg stands on one foot. His femur has cross-sectional area of 8.0 cm2 and uncompressed length 50 cm. (a) How much shorter is the femur when he stands on one foot? (b) What is...

Q: A plastic water bottle open at the top is three-fourths

A plastic water bottle open at the top is three-fourths full of water and is placed on a scale. The bottle has an indentation for a label midway up the side, and a strap has been placed around this in...

Q: How many moles of He are in 13 g of He?

How many moles of He are in 13 g of He?

Q: The diagram shows a simplified household circuit. Resistor r1 = 240

The diagram shows a simplified household circuit. Resistor r1 = 240.0 Ω represents a lightbulb; resistor r2 = 12.0 Ω represents a hair dryer. The resistors r = 0.50 Î&cop...

Q: A town is considering using its lake as a source of power

A town is considering using its lake as a source of power. The average temperature difference from the top to the bottom is 15°C, and the average surface temperature is 22°C. (a) Assuming that the to...

Q: Many homes are heated with “radiators,” which are hollow metal

Many homes are heated with “radiators,” which are hollow metal devices filled with hot water or steam and located in each room of the house. They are sometimes painted with metallic, high-gloss silver...

Q: A thin circular hoop is suspended from a knife edge. Its

A thin circular hoop is suspended from a knife edge. Its rotational inertia about the rotation axis (along the knife) is I = 2mr2. Show that it oscillates with the same frequency as a simple pendulum...

Q: In a nuclear reactor, a neutron moving at speed vi in

In a nuclear reactor, a neutron moving at speed vi in the positive x- direction strikes a deuteron, which is at rest. The neutron is deflected by 90.0° and moves off with speed 0.577vi in the positive...