Extra Problems

Here are some resources for extra problems related to Classical Mechanics:

Problems and Solutions in Introductory Mechanics, by David Morin

This is a new book by Morin (2014), which is aimed at a more introductory level than the 2008 version. Like that book, it gives a variety of problems, both multiple choice and written, with complete solutions available. It is self-published and very inexpensive. You can find it at amazon.com for less than $15 in paperback, a good investment for the extra practice it will give you. During the term I'll be recommending particular problems for study from this book, on this web page. To get you started, the authors has put the first four chapter of the book online at

http://www.people.fas.harvard.edu/~djmorin/book.html

Perhaps the most useful chapter in the book is the first one, where the author gives lots of useful advice about how to tackle physics problems. If you follow this advice, you are sure to do better in this course. It requires hard work, but this chapter is an excellent road map to follow as you struggle through the material. The single most important advice is something the author repeats several times, and which I'll emphasize also:

Don't just read the solutions through

Read just enough to see where you got stuck, and then stop reading the solutions and continue working on the problem yourself. This applies to working with other students as well. Don't just listen to other students explain how to do an entire problem. You won't be learning it this way. Do it on your own, and just ask for help on particular things you get stuck on. Once you see where you went wrong, continue to work on the problems yourself.

I've put a copy of this book in the physics reading room for use in OH118, and another copy of the book on reserve in Gordon Library.

Morin 2014 problems related to Study Guides 1 and 2

There are a number of problems related to circular motion and Newton's laws in chapters 3 and 4 of Morin's new book (see above). There are both multiple choice and problems to work out. Here are some suggested problems to try. Remember to work on these as much as possible without looking at the solutions!

Ch 3 Multiple Choice: 10, 11, 12, 13

Ch 3 Problems: 17, 21

Ch 4 Multiple Choice: 1, 3, 4, 5, 7, 8, 15, 17, 22, 23

Ch 4 Problems: 2, 3, 8, 9, 18, 24

Morin 2014 problems related to Study Guides 3 and 4

Here are some practice problems from Morin's new book (see above). There are both multiple choice and problems to work out. Remember to work on these as much as possible without looking at the solutions!

Ch 5 Multiple Choice: 1

Ch 5 Problems: 19, 22, 25 (part a)

Ch 6 Multiple Choice: 5, 18, 20

Ch 6 Problems: 25

Morin 2014 problems related to Study Guides 5 and 6

Here are some practice problems from Morin's new book (see above). There are both multiple choice and problems to work out. Remember to work on these as much as possible without looking at the solutions!

Ch 11 Multiple Choice: 3

Ch. 11 Problems: 6, 4, 17 (use the approach we have been learning in this course)

Extra asteroid orbit problems

Asteroid hits Earth problem /solutions

Saving the Earth problem /solutions

NASA moon bombing

A while back NASA fired projectiles into moon's surface to learn about its composition. For extra practice, do this problem:

• A rocket is initially in a circular orbit around the moon, at a distance r_0 from the moon's center. Take the radius of the moon as R, and assume that r_0 = 2.5 R. If the rocket's thrusters are fired in the forward direction (to slow it down), what fractional change in speed is needed in order that the rocket hit the moon? Assume that the rocket's speed changes very fast compared to the motion of the rocket around the moon.
• Solutions