College Physics Study Set 7

The first experiment, which systematically demonstrated the equivalence of mechanical energy and heat, was performed by:

Who demonstrated that when heat is gained or lost by a system during some process, the gain or loss can be accounted for by an equivalent quantity of mechanical work done on the system?

A 10-kg piece of aluminum (which has a specific heat of 900 J/kgC) is warmed so that its temperature increases by 5.0 C.How much heat was transferred into it?

Which of the following statements is true?

A swimming pool heater has to be able to raise the temperature of the 40 000 gallons of water in the pool by 10.0 C.How many kilowatt-hours of energy are required? (One gallon of water has a mass of approximately 3.8 kg and the specific heat of water is 4 186 J/kgC.)

An inventor develops a stationary cycling device by which an individual, while pedaling, can convert all of the energy expended into heat for warming water.What minimum power must be generated if 300 g water (enough for 1 cup of coffee) is to be heated in 10 min from 20C to 95C? (1 cal = 4.186 J, the specific heat of water is 4 186 J/kgC)

On a sunny day at the beach, the reason the sand gets so hot and the water stays relatively cool is attributed to the difference in which property between water and sand?

Arrange from smallest to largest: the BTU, the joule, and the calorie.

A 3.00-g lead bullet is traveling at a speed of 240 m/s when it embeds in a wood post.If we assume that half of the resultant heat energy generated remains with the bullet, what is the increase in temperature of the embedded bullet? (specific heat of lead = 0.030 5 kcal/kgC, 1 kcal = 4 186 J)

Heat flow occurs between two bodies in thermal contact when they differ in what property?

Marc attaches a falling 500-kg object with a rope through a pulley to a paddle wheel shaft.He places the system in a well-insulated tank holding 25 kg of water.When the object falls, it causes the paddle wheel to rotate and churn the water.If the object falls a vertical distance of 100 m at constant speed, what is the temperature change of the water? (1 kcal = 4 186 J, the specific heat of water is 4 186 J/kgC, and g = 9.8 m/s²)

A solar heated house loses about 5.4 * 10⁷ cal through its outer surfaces on a typical 24-h winter day.What mass of storage rock is needed to provide this amount of heat if it is brought up to initial temperature of 62C by the solar collectors and the house is maintained at 20C? (Specific heat of rock is 0.21 cal/gC.)

A waterfall is 145 m high.What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s², c_w = 4 186 J/kgC)

Sea breezes that occur near the shore are attributed to a difference between land and water with respect to what property?

An inventor develops a stationary cycling device by which an individual, while pedaling, can convert all of the energy expended into heat for warming water.How much mechanical energy is required to increase the temperature of 300 g of water (enough for 1 cup of coffee) from 20C to 95C? (1 cal = 4.186 J, the specific heat of water is 4 186 J/kgC)

A 0.2-kg aluminum plate, initially at 20C, slides down a 15-m-long surface, inclined at a 30 angle to the horizontal.The force of kinetic friction exactly balances the component of gravity down the plane so that the plate, once started, glides down at constant velocity.If 90% of the mechanical energy of the system is absorbed by the aluminum, what is its temperature increase at the bottom of the incline? (Specific heat for aluminum is 900 J/kgC.)

How many calories are equal to one BTU? (One calorie = 4.186 J, one BTU = 1 054 J.)

Of the following systems, which contains the most heat?

Calories of the food type are equal to which of the following?

If heat is flowing from a table to a block of ice moving across the table, which of the following must be true?