Which statement best describes the relationship between a baseball’s potential and kinetic energy after it is thrown? (assume the ball travels in a straight line)(1 point)
Potential energy decreases as kinetic energy increases.
Potential energy decreases as kinetic energy increases.
Potential energy does not change, and kinetic energy decreases.
Potential energy does not change, and kinetic energy decreases.
Potential and kinetic energy both decrease.
Potential and kinetic energy both decrease.
Potential energy increases, and kinetic energy does not change.
The statement "Potential energy decreases as kinetic energy increases" best describes the relationship between a baseball's potential and kinetic energy after it is thrown.
A student bounces a tennis ball. She drops the ball, and then it bounces back up to her. When does the ball have zero kinetic energy?(1 point)
Responses
As soon as she drops it
As soon as she drops it
Just after it hits the ground
Just after it hits the ground
Exactly when it hits the ground
Exactly when it hits the ground
At the very top of its bounce
At the very top of its bounce
As shown below, a student places a 500-gram car at point X on a wooden racetrack in an energy transformation investigation.
What outcome is most likely if the student uses a 700-gram car instead?
A 700-gram car would have more kinetic energy at point X and less potential energy at the bottom of the racetrack
A 700-gram car would have more kinetic energy at point X and less potential energy at the bottom of the racetrack
A 700-gram car would have less kinetic energy at point X and less potential energy at the bottom of the racetrack
A 700-gram car would have less kinetic energy at point X and less potential energy at the bottom of the racetrack
A 700-gram car would have less potential energy at point X and less kinetic energy at the bottom of the racetrack
A 700-gram car would have less potential energy at point X and less kinetic energy at the bottom of the racetrack
A 700-gram car would have more potential energy at point X and more kinetic energy at the bottom of the racetrack
A 700-gram car would have more potential energy at point X and more kinetic energy at the bottom of the racetrack.
The universe’s total amount of energy does not ever change, but the amount of this energy that is available to do work varies tremendously. What statement best explains the changes in available energy?(1 point)
100% of energy is always converted with perfect efficiency.
100% of energy is always converted with perfect efficiency.
Energy constantly changes from one form to another.
Energy constantly changes from one form to another.
Energy transfer always occurs through heat.
Energy transfer always occurs through heat.
The only way to create energy is through nuclear reactions.
The only way to create energy is through nuclear reactions.
The statement "Energy constantly changes from one form to another" best explains the changes in available energy.
Lucy is making a cup of hot chocolate. She puts the chocolate and hot water into a cup, and stirs the mixture.
A few minutes later, she notices the cup and the spoon have gotten hot. What made Lucy’s cup and spoon get hot?
(1 point)
Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.
Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules moved through the cooler molecules in the surrounding air and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules moved through the cooler molecules in the surrounding air and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules radiated into the cooler molecules of the hot chocolate mix and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules radiated into the cooler molecules of the hot chocolate mix and transferred heat.
Heat was transferred through conduction to the cup and spoon when the hot water molecules flowed in currents through the cooler molecules of the hot chocolate mix and transferred heat.
Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.
The picture below shows two flasks, one with hot water and one with room temperature water, which are connected by a conductive metal bar.
In which direction does the thermal energy between the flasks flow?
(1 point)
Thermal energy flows from the flask with hot water to the flask with room temperature water.
Thermal energy flows from the flask with hot water to the flask with room temperature water.
Thermal energy does not flow between the two flasks.
Thermal energy does not flow between the two flasks.
Thermal energy flows from the flask with room temperature water to the flask with hot water.
Thermal energy flows from the flask with room temperature water to the flask with hot water.
Thermal energy flows equally between the two flasks.
Thermal energy flows equally between the two flasks.