Kinetic and Potential Energy

Front

Which factor(s) affect how much kinetic energy the sled and its team have when the sled crosses the finish line?

Back

speed and mass

Answer explanation

The correct answer is C. Kinetic energy depends on the speed and the mass of the object. Time is not a separate factor affecting kinetic energy. It is included in speed, which is distance per time.

Front

Which cylinder has the rubber band with the greatest elastic potential energy? Options: 5 cm, 10 cm, 20 cm, 25 cm.

Back

25 centimeter

Answer explanation

The correct answer is D. Elastic potential energy is based on how much an object is stretched or compressed. For a rubber band, it is based on how much it is stretched. The larger the object is that the rubber band has to go around, the more the rubber band is stretched, and the greater its elastic potential energy.

Front

Where will the water have greater gravitational potential energy to be converted into electricity: Site A (50-meter waterfall) or Site B (35-meter waterfall)?

Back

Site A

Answer explanation

The correct answer is A. Gravitational potential energy is the energy stored in an object due to its position above the Earth’s surface as a result of the force of gravity acting on the object. The higher the object is above the surface of Earth, the greater the stored energy is. The object in this case is the water stored behind the dam. This means, the higher the dam is built above the Earth’s surface the more potential energy the water mass has and the more electricity can be generated.

Front

Which of the following is an example of kinetic energy?

• a roller coaster paused at its highest point
• a bicycle rolling downhill
• a boulder sitting at the top of a mountain
• a ball at the top of its trajectory

Back

a bicycle rolling downhill

Answer explanation

The correct answer is B. Kinetic energy is the energy of motion. The bicycle rolling downhill is using energy of motion. A roller coaster paused at its highest point, a boulder sitting at the top of a mountain, and a ball at the top of its trajectory are describe moments where those objects have potential, or stored, energy.

Front

The gravitational potential energy (GPE) of a 20-N bird feeder on a 2-m pole is the result of ________________.

Back

its gravitational pull of the Earth

Answer explanation

The correct answer is the gravitational pull of Earth. Gravitational potential energy is the product of weight and height.

Front

At what point on the track does the car have the greatest potential energy? The greatest kinetic energy? Options: At the ending point; at the starting point, At the starting point; at the ending point, At the highest point on the track; at the lowest point on the track, At the lowest point on the track; at the highest point on the track

Back

At the highest point on the track; at the lowest point on the track

Answer explanation

The correct answer is C. Potential energy is highest at the highest point on the track, so A, B, and D are not correct.

Front

Types of energy: chemical, electrical, electromagnetic, mechanical, nuclear, thermal. Classify 'thermal' energy as kinetic, potential, or both.

Back

Kinetic energy

Answer explanation

The correct answer is D. Thermal energy is the kinetic energy of atoms and molecules. A, B, and C are all forms of energy may be potential energy, so A, B, and C are not correct.

Front

What type of energy is transformed into the kinetic energy Johanna uses when pushing her brother on a swing?

Back

chemical

Answer explanation

The correct answer is A. Johanna must use chemical energy that she has gotten from food she eats. Johanna does not get any of those types of energy from food, so B, C, and D are not correct