Physics 1116 Fall 2011 Homework 5 Due: Friday, Sep 30

Reading: KK Ch. 3 & Note 3.1

1. Calculate center-of-mass.

a. Catenary, y(x) = cosh x between x = ±x0.

b. disk with disk cut out

2. Exploding projectile. KK 3.4

3. Springy blocks. KK 3.7

4. Continuous flow. KK 3.16

5. Rocket. KK 3.20

6. A Classic Problem. A dog of mass m = 10kg is standing at one end of a raft whichis floating in a lake; the dog is 10m from the shore. The raft can glide in the waterwithout any friction. The raft has a mass M = 40kg and length L = 7m long; themass is uniformly distributed. The dog walks 5m on the raft towards shore and thensits down. How far is he from shore?