1. 7.2 Work Done by a Constant Force 7.1 Work done by a constant force The work, W, done on a system by an agent exerting a constant force on the system is the product of the magnitude F of the force, the magnitude  r of the displacement of the point of application of the force, and cos  where  is the angle between the force and the displacement vectors: W = F  r cos 

2. 7.3 The Scalar Product of Two Vectors 7.2 Scalar product of any two vectors and 7.3 7.4 7.5 7.6

3. 7.4 Work Done by a Varying Force 7.7 7.8 7.9 Spring force 7.10 7.11 7.12 7.13 F s = - kx

4. 7.5 Kinetic Energy and the Work–Kinetic Energy Theorem 7.14 7.15 7.16 7.17 K = ½ mv 2

5. 7.6 Potential Energy of a System 7.18 7.19 7.20 7.21 7.22 U g = mgy W net =  U g W app = ½ kx f 2 – ½ kx i 2

6. 7.7 Conservative and Nonconservative Forces 7.23 7.24 W C = U i - U f -  U

7. 7.8 Relationship Between Conservative Forces and Potential Energy 7.25 7.26 7.27 dU = ¯ F x dx 7.28