7. In an investigation of energy transfer, a student observes a roller coaster at locations A, B, C, and D. Then she creates the graph below of the roller coaster’s potential and kinetic energy at each location.

The statement "The roller coaster’s kinetic and potential energy change from location to the next, but its total energy remains the same" is true according to the graph.

9. Rebecca climbs the ladder of a large water slide, waits her turn at the top, and then slides down the slide into a pool. Which answer best describes the energy changes during her time on the slide?(1 point)

Responses

potential → kinetic → potential
potential → kinetic → potential

kinetic → mechanical → potential
kinetic → mechanical → potential

potential → mechanical → kinetic
potential → mechanical → kinetic

kinetic → potential → kinetic

The best answer is "potential → kinetic → potential".

8. The pendulum in the diagram below swings from position A to B.

If we don’t consider friction, what happens to the total mechanical energy as the pendulum swings from position A to position B?

(1 point)
Responses

It becomes greater.
It becomes greater.

It remains the same
It remains the same

It declines
It declines

It is not conserved

The total mechanical energy remains the same as the pendulum swings from position A to position B.

14. As energy is transferred or conserved, some of that energy becomes unavailable to do work. What happens to this unavailable energy?(1 point)

Responses

The unavailable energy is given off as microwaves
The unavailable energy is given off as microwaves

The unavailable energy is destroyed
The unavailable energy is destroyed

The unavailable energy is given off as heat
The unavailable energy is given off as heat

The unavailable energy is conducted

The unavailable energy is given off as heat.

16. An aluminum block has a starting temperature of 300oC. The block is placed into 200 milliliters of water, which has a temperature of 20oC. What heat transfer will occur?(1 point)

Responses

Heat will flow from the block to the water until both substances have the same temperature as their container.
Heat will flow from the block to the water until both substances have the same temperature as their container.

Heat will flow from the block to the water until both substances have a temperature of 20 degrees Celcius.
Heat will flow from the block to the water until both substances have a temperature of 20 degrees Celcius.

Heat will flow from the block to the water until both substances have a temperature between 20 degrees Celsius and 300 degrees Celcius.
Heat will flow from the block to the water until both substances have a temperature between 20 degrees Celsius and 300 degrees Celcius.

Heat will flow from the block to the water until both have a temperature of 300oC.

Heat will flow from the block to the water until both substances have the same temperature as their container.

17. Two samples of pure water are mixed with food coloring. One sample is red, and the other is blue. When the two water samples are combined, the red water floats on top of the blue water. Which statement best explains this result? (1 point)

Responses

The blue water is warmer and is more dense.
The blue water is warmer and is more dense.

The red water is colder and is more dense.
The red water is colder and is more dense.

The red water is warmer and is less dense.
The red water is warmer and is less dense.

The blue water is colder and is less dense.

The blue water is colder and is more dense.

18. Which investigation would best show the transfer of heat energy without any type of matter as a medium?(1 point)

Responses

an investigation of radiation using electromagnetic waves
an investigation of radiation using electromagnetic waves

an investigation of radiation using a current within a fluid
an investigation of radiation using a current within a fluid

an investigation of conduction through movement of particles within a solid
an investigation of conduction through movement of particles within a solid

an investigation of conduction using collisions between particles

An investigation of radiation using electromagnetic waves would best show the transfer of heat energy without any type of matter as a medium.

19. Convection ovens cook food more evenly than a standard thermal oven. Which statement explains how a convection oven works?(1 point)

Responses

Hot air is transferred through direct molecule contact.
Hot air is transferred through direct molecule contact.

Hot air is transferred through density differences when hot air rises and cool air sinks.
Hot air is transferred through density differences when hot air rises and cool air sinks.

Hot air is transferred when heat radiates from a thermal burner.
Hot air is transferred when heat radiates from a thermal burner.

Hot air is transferred through density differences when cool air rises and hot air sinks.

Hot air is transferred through density differences when hot air rises and cool air sinks.

20. People use oven mitts to avoid getting burns when moving hot metal pans while cooking. Which physical property of the metal pan requires the use of an oven mitt when it is hot?(1 point)

Responses

High thermal conductivity
High thermal conductivity

Low thermal conductivity
Low thermal conductivity

High solubility
High solubility

Low magnetism

High thermal conductivity requires the use of an oven mitt when a metal pan is hot.