Study Guide | Unit D Energy Test ANSWER KEY FOR GRADE 6

Jose had a 200 mL cup of hot chocolate that was 95º Celsius which was too hot to drink. His mother suggested he add some cold milk to cool it off so he added 50 mL of milk which was 5º Celsius. What was the approximate temperature of Jose's hot chocolate?

75º Celsius

Which of the following is an example of chemical energy being transformed into thermal energy?

A match is burned.

Which statement most accurately describes the Law of Conservation of Energy?

Energy can not be created or destroyed but it can change from one type of another.

An increase in thermal energy in the atmosphere may result in:

More Hurricanes

At which point(s) is the gravitational potential energy the highest?

Points A and E

The efficiency of an average gasoline powered car is about 20%. This means,

The car uses 20% of the energy stored in the gasoline for motion.

If you placed an object that was 90º Celsius in a room that is 25º Celsius, which of the following statements is correct?

Thermal energy from the hot object will be transferred from the object to the air in the room.

When you open the door to a refrigerator for a minute, what happens?

Thermal energy in the air outside the refrigerator is transferred to the inside of the refrigerator.

On a summer day, asphalt is hot on your bare feet because the asphalt has _____________ thermal energy from the sun.

absorbed

The amount of thermal energy that can be stored in an object depends on:

all of the above.

Energy from the sun is transformed _______ energy by plants.

chemical energy

What energy transformation takes place when a radio is plugged in and turned on?

electrical to sound

Objects of different masses are suspended from a given height. Which combination will have the most potential energy?

high mass and high height

Which of the following light bulbs is most efficient?

light bulb 2

Cory noticed that the hood of the car was hot after driving it for a while. What energy transformation was she noticing?

motion (kinetic) - thermal energy

At which point(s) is energy being transformed from kinetic energy of motion to gravitational potential energy as the skateboarder goes back and forth on the track?

points B and D

The following methods will melt an ice cube quickly, except

put it in an insulating container.

Energy from the Sun reaches the Earth through a type of energy transfer known as:

radiation

Putting reflecting films on your car windows helps keep the interior cool by

reflecting sunlight

Rubbing two wooden sticks together can sometimes result in a fire. What would increase the probability of a fire starting?

rubbing the sticks together more quickly

A steel fork and a plastic spoon are both at the same temperature. The fork feels colder when you touch it. This is because:

steel conducts thermal energy better than plastic.

A liquid evaporates when the faster moving molecules escape from the liquid. When this happens:

the temperature of the liquid decreases.

Heating an object to a higher temperature increases that object's:

thermal energy

One way a solar oven works is by transferring energy from the sun to:

thermal energy in water or food