PHY Q10

Which of the following temperatures is the lowest? 263 K. 0°C. 0°F. All are the same.

0°F.

A physics student has to make a choice in the color of paint to put on her geosynchronous communication satellite, MYSAT1. Considering most of its orbit is in sunlight, the decision of a light versus dark color paint will depend on which concept below? A dark paint would overheat the satellite when it passes through Earth's shadow but not in sunlight. A light paint would be better for keeping the satellite cool in sunlight. A dark paint would be better for keeping the satellite cool in sunlight. A light paint would be better in the sunlight and in Earth's shadow for preventing overheating.

A light paint would be better for keeping the satellite cool in sunlight.

Which of the following units is not an energy unit? Calorie Kilocalorie Kilowatt-hour Joule Horsepower

Horsepower

Water freezes at 273° on the ________ scale. Fahrenheit Vernier Celsius Rankin Kelvin

Kelvin

Which object is hotter? Object 1 at T = 0° C. Object 2 at T = 0° F. Object 3 at T = 0 K.

Object 1 at T = 0° C.

Objects A and B are at the same temperature. Object A now has its temperature increased by one Fahrenheit degree, while B has its temperature increased by one Kelvin degree. Which object now has higher temperature? It is impossible to tell from this data. Object A. Both have the same temperature. Object B.

Object B.

Which process does not transfer heat energy between objects? Reflection. Conduction. Radiation. Convection.

Reflection.

Four samples of steel, lead, alcohol, and glass all have the same mass and are all initially at 20°C. After 100 calories of heat are added to each sample, the final temperatures are 38.2°C for the steel, 85.6°C for the lead, 23.4°C for the alcohol, and 30°C for the glass. Which of these four materials has the largest specific heat capacity? The lead. The glass. The steel. The alcohol. All have the same heat capacity, since all absorbed 100 cal of heat.

The alcohol.

Two identical objects, one light colored and the other dark colored, are at the same elevated temperature, 50°C. You now place them in a dark, much cooler room. Which object will reach the room's temperature first? The light colored object As strange as it seems, neither object will ever reach room temperature because energy conservation prevents the loss of energy. Both reach room temperature at same time. The dark colored object

The dark colored object

Two identical objects, one light colored and the other dark colored, are at the same cool temperature. Then, you place them outside, on a warm day, in direct sunlight. Which object will warm up faster? The dark one The light one Both warm up at the same rate. As strange as it seems, neither object will ever warm up because energy conservation prevents the addition of energy.

The dark one

Compare the internal energy of one gram of steam to that of one gram of water if both are at 100°C. The internal energy of the water will be higher. The internal energy of the water and steam are the same. The internal energy of the steam will be higher.

The internal energy of the steam will be higher.

You lose your left sandal during a hot afternoon at the beach. Thus, you must hike back to your vehicle with one bare foot across the burning sand. Why does the bare foot get so much hotter? Heat flows from your right foot into your left foot and then out into the sand, thus cooling off your right foot. The sandal insulates the right foot from the hot sand. The sandal conducts heat away from your right foot and into the sand. The sandal is in the shadow of your foot, but the sand is not.

The sandal insulates the right foot from the hot sand.

On a cold winter's morning you awake and step out of bed. One foot is on the tile floor and the other is on a rug on the floor. Which statement is true? The tile feels colder because it conducts heat more rapidly away from your foot. The tile feels colder because it is smoother than the rug. The tile feels colder because it cannot absorb water like the rug can. The tile feels colder because it is connected to the cold ground outside.

The tile feels colder because it conducts heat more rapidly away from your foot.

The lowest possible temperature a body can approach is called critical temperature. absolute zero. "mighty" cold. triple absolute zero. triple point.

absolute zero.

Absolute zero is the temperature of the freezing point of mercury. of the freezing point of water. of the boiling point of liquid helium. at which an ideal gas would exert zero pressure. on the coldest day recorded at Nome, Alaska.

at which an ideal gas would exert zero pressure.

Water in a dish is set on a table in an initially empty closed room and begins to evaporate. The temperature in the room will remain the same. begin to decrease. begin to increase. not be able to be predicted based on the information given.

begin to increase.

Hot cider is poured into a metal cup. Shortly thereafter the handle of the cup becomes hot. This is due to the process of conduction. osmosis. radiation. convection.

conduction.

During the course of a demonstration the professor is called away. When he returns he finds a beaker of water that was at room temperature is now at a slightly higher temperature. There is a stirring rod on the desk and a cigarette lighter. The professor can assume that the temperature increase is due to heat added to the system. mechanical work done on the system. either heat added or mechanical work done.

either heat added or mechanical work done.

The term heat in physics is equivalent to temperature. the same as work. equivalent to internal energy. energy transferred to a body because of a difference in temperature. any energy transferred to a body that raises the temperature of the body.

energy transferred to a body because of a difference in temperature.

Heat is a form of energy, and it has long been known that heat energy will naturally flow from liquids to solids, except when the solid is melting. from solids to liquids, but only when the solid is melting. from hot to cold objects. from cold to hot objects.

from hot to cold objects.

After working hard outside on a hot summer day, placing a towel soaked in cold water on your head can feel very good. The reason the towel feels cold to you is that cold air from the towel convects to your head. low temperature heat from the towel conducts to your head, lowering your temperature. heat conducts from your head to the towel, lowering your temperature. cold air radiates from the towel to your head.

heat conducts from your head to the towel, lowering your temperature.

The amount of heat is often measured in calories. If I add 1 calorie of heat energy to 1 gram of water, the temperature of the water will stay the same, since water has a very high specific heat. decrease by 1°F. increase by 1°C. decrease by 1°C. increase by 1°F.

increase by 1°C.

When the temperature of the air in a balloon is raised, the volume of the balloon increases. decreases. stays the same.

increases.

If you stand near a large fire, your face will be cooler if you place your hand between your face and the fire. Your hand is preventing heat flow by latent heat. convection. conduction. radiation.

radiation.

The air at the beach is the same temperature everywhere, but you feel cooler under a beach umbrella because a convection cell forms under the umbrella, thereby cooling you off. the umbrella gets hot, which thereby cools off the air underneath it. solar radiation is not heating up your skin. the sand underneath you cools off more rapidly than the water vapor in the air.

solar radiation is not heating up your skin.

The temperature of a sample of a substance is a way to gauge the kinetic energy of the fastest moving molecule in the sample. the average momentum of the fastest 50% of the molecules in the sample. the average kinetic energy of the molecules in that sample. the average momentum of the molecules in a sample.

the average kinetic energy of the molecules in that sample.

Heat flows into a gas in a piston and the gas performs some work on its surroundings. The amount of work done is less than the heat added. In this situation, the internal energy of the gas decreased. the internal energy of the gas did not change. the internal energy of the gas increased. energy is not conserved and so it cannot happen. the gas experienced a phase change.

the internal energy of the gas increased.

After I dip a cup of water from the ocean, I can conclude that the temperatures are the same but the water in the cup has more energy the ocean temperature is higher because it has more molecules in it. the temperature of the water in the cup is the same as the temperature of the water in the ocean. the ocean temperature is higher because it never loses its heat.

the temperature of the water in the cup is the same as the temperature of the water in the ocean.

On a cold day, a metal fence post feels colder to the touch than a tree. This sensation of different temperatures is explained by the fact that the specific heat capacity of the metal is higher. the thermal conductivity of the wood in the tree is higher. the specific heat capacity of the wood in the tree is higher. the temperature of the tree is higher. the thermal conductivity of the metal is higher.

the thermal conductivity of the metal is higher.

An ice cube is floating in a glass of water with the water level just reaching the top of the glass. If the temperature in the surrounding area is above freezing, the ice cube will melt. When it does, the water level in the glass will remain unchanged as the ice continues to melt. water will begin to spill over the top of the glass. the water level in the glass will begin to go down. it is impossible to tell what the water level will do from the information given.

the water level in the glass will remain unchanged as the ice continues to melt.

Heat is added to an ideal gas and the gas expands. In such a process the temperature must always decrease. will remain the same if the work done equals the heat added. must always increase. will remain the same if the work done is less than the heat added. will remain the same if the work done exceeds the heat added.

will remain the same if the work done equals the heat added.

Whenever a gas is compressed, the temperature of the gas must get smaller. work must be done on the gas. its internal energy must get smaller. heat must leave the gas.

work must be done on the gas.

When you apply an alcohol swab to your skin, it feels cool because germs are destroyed by the alcohol, and they give off cold heat as they die. your skin transfers a bit of heat to the liquid alcohol and the alcohol evaporates. the density of alcohol is less than 1 g per cm3. of nothing—it is an illusion, because evaporating alcohol is actually hotter than liquid alcohol.

your skin transfers a bit of heat to the liquid alcohol and the alcohol evaporates.