Work, energy and power 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. A force of 10 N acts at 60° to the direction of motion of an object that moves 5.0 m. How much work does it do?
- A. 50 J
- B. 43 J
- C. 25 J
- D. 5.0 J
2. A machine does 3000 J of work in 40 s. What is its power?
- A. 120 kW
- B. 75 W
- C. 0.013 W
- D. 3040 W
3. A lorry moves at constant speed 20 m s⁻¹ with a driving force of 2.5 kN. What is the useful power?
- A. 8.0 × 10⁻³ W
- B. 125 W
- C. 2.5 kW
- D. 50 kW
4. A motor delivers 600 W of useful power while the electrical input power is 800 W. What is its efficiency?
- A. 75%
- B. 133%
- C. 25%
- D. 200 W
5. The force-displacement graph for a force is a straight line from 0 N to 30 N over 2.0 m. What is the work done?
- A. 15 J
- B. 60 J
- C. 30 J
- D. 32 J