Energy Transfers, Conservation & Dissipation of Energy Quiz
Studying this course? Keep your progress in one place.
Pick an answer for each. Quizzes never use energy.
5 questions, one answer each
Each answer is checked as you go, with why.
See all 5 questions
1. What does the law of conservation of energy state?
- A. A. Energy can be created but not destroyed
- B. B. Energy cannot be created or destroyed, only transferred or dissipated
- C. C. Energy is destroyed when it is dissipated
- D. D. Useful energy is always greater than wasted energy
2. At the very bottom of a pendulum's swing, which energy store is greatest?
- A. A. Gravitational potential
- B. B. Elastic potential
- C. C. Kinetic
- D. D. Chemical
3. A motor has a total energy input of 500 J and dissipates 100 J as heat. What is its efficiency?
- A. A. 20%
- B. B. 50%
- C. C. 80%
- D. D. 100%
4. In a Sankey diagram for an energy-transferring device, what does the width of each arrow represent?
- A. A. The speed of the transfer
- B. B. The amount of energy transferred
- C. C. The efficiency as a percentage
- D. D. The time taken for the transfer
5. A car's brakes get hot when it stops. Which statement best explains this in terms of energy?
- A. A. Kinetic energy is destroyed by the brakes
- B. B. Kinetic energy is transferred and dissipated as heat by friction
- C. C. Gravitational potential energy is converted to chemical energy
- D. D. The brakes create new thermal energy