Law of Conservation of Energy Exam

A roller coaster car is at the top of a hill. Describe the energy transformation that occurs as it descends the hill.

• Kinetic energy is transformed into potential energy.

• Potential energy is transformed into kinetic energy.

• Thermal energy is transformed into potential energy.

• Chemical energy is transformed into kinetic energy.

A pendulum is released from a certain height. At what point in its swing does it have the maximum kinetic energy?

• At the highest point of the swing.

• At the lowest point of the swing.

• Halfway between the highest and lowest points.

• It has constant kinetic energy throughout.

Explain how the law of conservation of energy applies to a closed system where a ball is thrown upwards and then falls back down.

• The total energy of the system increases as the ball moves.

• The total energy of the system decreases as the ball moves.

• The total energy of the system remains constant, with energy transforming between kinetic and potential forms.

• The total energy of the system is lost to the surroundings.

• 49 J

• 98 J

• 490 J

• 980 J

In a hydroelectric power plant, water stored at a height is used to generate electricity. Identify the energy transformations that occur in this process.

• Chemical energy to electrical energy.

• Potential energy to kinetic energy to electrical energy.

• Thermal energy to mechanical energy to electrical energy.

• Kinetic energy to potential energy to electrical energy.

A car engine converts chemical energy from fuel into mechanical energy. Discuss how the law of conservation of energy is demonstrated in this process, considering energy losses.

• All chemical energy is converted into mechanical energy with no losses.

• Some chemical energy is converted into mechanical energy, while some is lost as thermal energy due to friction and heat.

• Mechanical energy is converted back into chemical energy.

• Chemical energy is completely lost in the process.

• 0.5 J

• 1 J

• 2 J

• 10 J

Consider a satellite orbiting Earth. Explain how the law of conservation of energy applies to the satellite's motion.

• The satellite's total energy increases as it moves closer to Earth.

• The satellite's total energy decreases as it moves further from Earth.

• The satellite's total energy remains constant, with energy transforming between kinetic and potential forms.

• The satellite's energy is lost to space.