1. Chapter 7 Kinetic Energy and Work 第7章 動能與功

2. Chapter 7 Kinetic Energy and Work
7-1 What is Physics?
7-2 What is Energy?
7-3 Kinetic Energy
7-4 Work
7-5 Work and Kinetic Energy
7-6 Work Done by the Gravitational Force
7-7 Work Done by a Spring Force
7-8 Work Done by a General Variable Force
7-9 Power

3. 7-1 What is Physics?
Energy 能量、能

4. 7-2 What is Energy? Principle of Energy Conservation Kinetic Energy 動能
Work 功

5. 7-3 Kinetic Energy
Kinetic energy K is energy associated with the state of motion of an object.
Joule (J) 焦耳
locomotive 機車（火車頭）
throttle 節流閥、節氣閥、油門

7. 7-4 Work Work W is said to be done on the object by the force.
Work W is energy transferred to or from an object by means of a force acting on the object. Energy transferred to the object is positive work, and energy transferred from the object is negative work.

8. 7-5 Work and Kinetic Energy
A force does positive work when it has a vector component in the same direction as the displacement, and it does negative work when it has a vector component in the opposite direction. It does zero work when it has no such vector component.
Work-Kinetic Energy Theorem 功能定理

12. Sample Problem

13. Sample Problem

14. 7-6 Work Done by the Gravitational Force

16. Sample Problem

17. 7-7 Work Done by a Spring Force
Hooke’s law 虎克定律
spring constant 彈性常數
spring force constant 彈力常數

18. Sample Problem

19. 7-8 Work Done by a General Variable Force

20. Sample Problem

21. 7-9 Power
power 功率
watt (W) 瓦特

23. Sample Problem