How Do You Approach Unique Physics Problems?

[Gokul43201]

Anyone worked on problems from "Thinking Like a Physicist" ? This is a compilation of qualifier problems from the University of Bristol (I think) Physics Dept. - very different from the standard physics problems you come across in texts like Irodov, Resnick, etc.

I found them quite refreshing !

 

[MathematicalPhysicist]

any particular problem in the book you found mind boggling? (that makes you look like this:
).

 

[Gokul43201]

Most of the problems involve making order of magnitude estimates, using reasonable assumptions.

I think the first problem in the book went something like this :

"A widely dispersed collection of particles condense into a planet. If the planet's temperature is at its melting point, what is its radius ?"













Sweet and simple; the solution of this problem requires the application of just a few simple concepts (grav. PE of a sphere, energy conservation, specific heat). The important trick is deciding if a certain assumption is reasonable to make (neglect radiation, electrostatic PE).

If you solve the problem reasonably well, you find the radius of the planet to be of the order of Earth's radius. No surprise there - we do have a molten core. Then you ask yourself what would happen if the planet were much bigger than this critical radius - why, gas giants, of course !

Neat, wot ?