1.
You pick up a can of soda off of the countertop. The countertop underneath the can feels colder than the rest of the counter. Which explanation do you think is the best?
Correct Answer
C. Some heat has been transferred from the counter to the soda.
Explanation
2nd Law of Thermodynamics -- heat transfer is from hot to cold only -- messiness spreads.
2.
After cooking an egg in boiling water, you cool the egg by putting it into a bowl of cold water. Which of the following explains the egg’s cooling process?
Correct Answer
D. Energy is transferred from the egg to the water.
Explanation
2nd Law -- heat goes from hot to cold.
3.
Why do we wear sweaters in cold weather?
Correct Answer
C. To reduce heat loss.
Explanation
We wear sweaters in cold weather to reduce heat loss. Sweaters act as insulating layers that trap our body heat and prevent it from escaping into the surrounding cold air. By reducing heat loss, sweaters help to keep us warm and maintain our body temperature in cold weather conditions. Wearing sweaters also helps to conserve energy as our bodies don't have to work as hard to generate heat.
4.
Amy wraps her dolls in blankets but can’t understand why they don’t warm up. Why don’t they warm up?
Correct Answer
C. The dolls are made of materials that don’t hold heat well.
Explanation
The dolls are made of materials that don't hold heat well. This means that they are not able to retain or trap heat within them. Therefore, even if Amy wraps them in blankets, the dolls will not warm up because the materials they are made of do not have the ability to hold onto heat.
5.
As water in a freezer turns into ice,
Correct Answer
C. The freezer air absorbs heat from the water.
Explanation
When water in a freezer turns into ice, the process involves the removal of heat energy from the water. As a result, the water loses heat to the surrounding air in the freezer. Therefore, the freezer air absorbs heat from the water.
6.
On a warm sunny day, you will feel cooler wearing light colored clothes because they
Correct Answer
A. Reflect more radiation.
Explanation
Light-colored clothes reflect more radiation, including sunlight, compared to dark-colored clothes. When radiation, such as sunlight, hits an object, it can be absorbed or reflected. Dark-colored clothes absorb more radiation, which leads to an increase in heat. On the other hand, light-colored clothes reflect more radiation, reducing the amount of heat absorbed by the body and making the person feel cooler.
7.
If you put a metal spoon and a wooden spoon into a pot of boiling water, one will become too hot to touch. Why?
Correct Answer
A. Metals conduct heat better than wood.
Explanation
Metals conduct heat better than wood because they have a higher thermal conductivity. This means that they are able to transfer heat more efficiently from the boiling water to the spoon. Wood, on the other hand, has a lower thermal conductivity, so it is not as effective at conducting heat. As a result, the metal spoon will become hotter than the wooden spoon when placed in the pot of boiling water.
8.
On a sunny day, the upstairs rooms in a house are usually hotter than the downstairs rooms. Why?
Correct Answer
B. Warm air rises and cool air sinks.
Explanation
Warm air rises and cool air sinks because of the principle of convection. When air is heated, it expands and becomes less dense, causing it to rise. As it rises, it creates a vacuum that pulls in cooler air from below, which then gets heated and rises as well. This creates a continuous cycle of warm air rising and cool air sinking. Therefore, on a sunny day, the upstairs rooms in a house are usually hotter than the downstairs rooms because warm air naturally rises upwards.
9.
You have a can of soda in your lunchbox that you want to keep cold. Which material will work best to keep it cold and why?
Correct Answer
D. Your wool sweater wrapped around the soda because wool traps air.
Explanation
Wool is a good insulator because it has a lot of air pockets within its fibers. When the soda is wrapped in a wool sweater, the air trapped within the wool acts as a barrier against heat transfer. This helps to keep the soda cold by preventing the outside temperature from reaching the soda and transferring heat to it.
10.
When you hold a metal coat hanger in a camp fire to roast a marshmallow, the coat hanger might get too hot to hold. Why might the coat hanger get too hot?
Correct Answer
C. Metal atoms vibrate with more energy when they get hot, and they collide with atoms near them, which makes the neighboring atoms vibrate too.
Explanation
When the metal coat hanger is exposed to the campfire, the heat causes the metal atoms to vibrate with more energy. These vibrating atoms then collide with neighboring atoms, transferring the energy and causing them to vibrate as well. This process continues, resulting in the heat spreading along the coat hanger. Eventually, the coat hanger becomes too hot to hold as the heat continues to transfer from atom to atom.
11.
An aluminum plate and a plastic plate have been in the freezer all night long. When you remove them the next morning,
Correct Answer
A. The plates have the same temperature.
Explanation
0th Law of Thermodynamics
12.
When placed in direct sunlight, which object will absorb the most radiation?
Correct Answer
D. A black sweater
Explanation
Dark colors absorb, light colors reflect.