Questions from College Physics

Q: (a) Calculate the work done by the engine during each

(a) Calculate the work done by the engine during each step and the net work done per cycle. (b) If the heat input per cycle is 58.3 kJ, what is the efficiency?

Q: The motor that drives a refrigerator produces 148 W of useful power

The motor that drives a refrigerator produces 148 W of useful power. The hot and cold temperatures of the heat reservoirs are 20.0°C and −5.0°C. What is the maximum possible amount of ice it can produ...

Q: (a) Find the heat flow into or out of the

(a) Find the heat flow into or out of the gas during each step, (b) Find the entropy change of the gas during the isothermal step. (c) What is the entropy change of the gas for a complete cycle? Is it...

Q: A new organic semiconductor device is able to generate electricity (which

A new organic semiconductor device is able to generate electricity (which can be used to charge a battery or light an LED) using the warmth of human skin. If your skin temperature is maintained by you...

Q: A model steam engine of 1.00 kg mass pulls eight

A model steam engine of 1.00 kg mass pulls eight cars of 1.00 kg mass each. The cars start at rest and reach a velocity of 3.00 m/s in a time of 3.00 s while moving a distance of 4.50 m. During that t...

Q: The human body could potentially serve as a very good thermal reservoir

The human body could potentially serve as a very good thermal reservoir, as its internal temperature remains quite constant at around 37°C and is stabilized by continual intake of food. Suppose an inv...

Q: A certain engine can propel a 1800 kg car from rest to

A certain engine can propel a 1800 kg car from rest to a speed of 27 m/s in 9.5 s with an efficiency of 27%. What are the rate of heat flow into the engine at the high temperature and the rate of heat...

Q: Two engines operate between the same two temperatures of 750 K and

Two engines operate between the same two temperatures of 750 K and 350 K, and have the same rate of heat input. One of the engines is a reversible engine with a power output of 23 kW. The second engin...

Q: In Problem 6, what is the pile driver’s speed just before

In Problem 6, what is the pile driver’s speed just before it strikes the pile?

Q: How many grams of carbohydrate does a person of mass 74 kg

How many grams of carbohydrate does a person of mass 74 kg need to metabolize to climb five flights of stairs (15 m height increase)? Each gram of carbohydrate provides 17.6 kJ of energy. Assume 10.0%...