Convection ovens cook food more evenly than a standard thermal oven. Which statement explains how a convection oven works?(1 point)
Responses
A. Hot air is transferred through density differences when cool air rises and hot air sinks.
B. Hot air is transferred through density differences when hot air rises and cool air sinks.
C. Hot air is transferred through direct molecule contact.
D. Hot air is transferred when heat radiates from a thermal burner.
B. Hot air is transferred through density differences when hot air rises and cool air sinks.
Which investigation would best show the transfer of heat energy without any type of matter as a medium?(1 point)
Responses
A. an investigation of conduction through movement of particles within a solid
B. an investigation of conduction using collisions between particles
C. an investigation of radiation using a current within a fluid
D. an investigation of radiation using electromagnetic waves
D. an investigation of radiation using electromagnetic waves
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
A. The red water is colder and is more dense.
B. The blue water is colder and is less dense.
C. The red water is warmer and is less dense.
D. The blue water is warmer and is more dense.
C. The red water is warmer and is less dense.
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
A. Heat will flow from the block to the water until both substances have a temperature between 20 degrees Celsius and 300 degrees Celcius.
B. Heat will flow from the block to the water until both substances have a temperature of 20 degrees Celcius.
C. Heat will flow from the block to the water until both substances have the same temperature as their container.
D. Heat will flow from the block to the water until both have a temperature of 300oC.
A. Heat will flow from the block to the water until both substances have a temperature between 20 degrees Celsius and 300 degrees Celcius.
Betsy uses an electric alarm clock to wake up for school. What energy transformation happens in the alarm clock to help her wake up?(1 point)
Responses
A. sound energy converts to kinetic energy
B. electrical energy converts to heat energy
C. electrical energy converts to sound energy
D. chemical energy converts to electrical energy
C. electrical energy converts to sound energy
10. Kim is upstairs, but walks downstairs to the kitchen for a snack. Which statement correctly describes the types of energy she has at the top of the stairs and as she walks down the stairs?(1 point)
A. potential energy at the top of the stairs; potential energy as she walks down
B. potential energy at the top of the stairs; kinetic energy as she walks down
C. kinetic energy at the top of the stairs; kinetic energy as she walks down
D. kinetic energy at the top of the stairs; potential energy as she walks down