| Last revised 1999/11/02 |
11. This problem illustrates that a quantity which has a given value at the beginning and at the end of a process doesn't necessarily have the same value throughout the process. You might find it instructive to sketch a graph of the position of the center of mass of soda + can as a function of the height of the soda that is left in the can.
16. Assume that the cannonballs are all stacked at the far left end of the car and that the thickness of the car's walls is negligible. In finding the maximum distance the car can possibly move, assume that you can adjust the mass of the car.
What is the total external force on car plus cannon plus cannonballs?
In part (c) of this problem, the book means any time after the last cannonball has come to rest at the right side of the car.
40. The problem asks for the linear momentum of the nucleus after the decay. Clearly this is a momentum problem, and in the absence of external forces it is a momentum conservation problem. Set up the problem by evaluating the total momentum of the entire system both before and after the decay. Why is energy not conserved?
47. Here you have three situations where you can evaluate momenta. You can work parts (b) and (c) together if you use m1 and m2 as symbols.
In order to get the book's answers, you must define the relative velocity as the difference between the velocity of the boat and the velocity of the thrown object after the throw is completed.
55. The indefinite integral with respect to time of m-1(t) (dm/dt) dt = ln (m) + C .