A student walks downstairs to class. Which statement correctly describes the types of energy the student has at the top of the stairs and as she walks down the stairs?
a
kinetic energy at the top of the stairs; potential energy as she walks down
b
kinetic energy at the top of the stairs; kinetic energy as she walks down
c
potential energy at the top of the stairs; kinetic energy as she walks down
d
potential energy at the top of the stairs; potential energy as she walks down
c
potential energy at the top of the stairs; kinetic energy as she walks down
When energy is conserved or transferred, some energy becomes unavailable to do useful work. What happened to the unavailable energy?
a
It is given off as heat.
b
It is conducted.
c
It is given off as microwaves.
d
It is completely destroyed.
a
It is given off as heat.
Two samples of water are prepared, one with red food coloring and one with blue. When carefully combined, the red-colored water is able to float on top of the blue-colored water. Which statement best explains this result?
a
The red-colored water is cooler and more dense.
b
The red-colored water is hotter and less dense.
c
The blue-colored water is cooler and less dense.
d
The blue-colored water is hotter and more dense.
c
The blue-colored water is cooler and less dense.
Betsy depends on her electric alarm clock every morning to get up in time for school. What energy transformation happens in Betsy's alarm clock to wake her up in the morning?
a
sound energy is converted to electrical energy
b
chemical energy is converted to kinetic energy
c
electrical energy is converted to thermal energy
d
electrical energy is converted to sound energy
d
electrical energy is converted to sound energy
Convection ovens are ovens that are advertised to cook food more evenly than a standard thermal oven. Which statement best explains how a convection oven works?
a
Hot air is transferred through heat being radiated from a thermal burner.
b
Hot air is transferred through density differences with cool air rising and hot air sinking.
c
Hot air is transferred through density differences with hot air rising and cool air sinking.
d
Hot air is transferred through molecule to molecule contact.
c
Hot air is transferred through density differences with hot air rising and cool air sinking.
Rita climbs a ladder to the top of a water slide, waits her turn, and then slides down the slide into a pool. Which series describes the energy changes of her actions?
a
potential → kinetic → potential
b
kinetic → mechanical → potential
c
potential → mechanical → kinetic
d
kinetic → potential → kinetic