# PF Insight Scavenger Hunt 2

Common Topics: insights, remember, amazing, linked, score

We have an amazing count of over 320 Insights published at Physics Forums. Now we test to see how much you remember from some of them. If you need a hint feel free to read the corresponding Insight which is linked at the end of the question. Good Luck and remember to read future Insights as there will be more hunts on the way! Don’t forget to add your score to the comments.

1. What paper won the Gravity Research Foundation essay contest in 1990? (link)

2. Two observers watch a block slide down a frictionless incline under the influence of gravity from point A to point B. Observer 1 is at rest relative to the incline, but observer 2 is moving at constant horizontal velocity. Consider the following quantities:
I. Work done by the normal force on the block.
II. Work done by gravity on the block.
III. Total mechanical energy of the block.

Which of these quantities will have the same value according to the two observers? (link)

3. Which of the following is the only correct statement about irreversible processes applied to a system? (link)

4. What is the predicted probability that a Higgs boson decays to b-quarks? (link)

5. What is true of the Jeans instability? (link)

7. From a scientific (as opposed to a popular) point of view, how do virtual particles get the energy needed to pop into existence? (link)

8. Which lens aberration cannot be controlled by stopping down your lens? (link)

9. Equal intervals of proper time for different observers can be represented by “clock diamonds” on a spacetime diagram. With the help of rotated graph paper, these clock diamonds are drawn with (link)

10. Mentor stevendaryl’s favorite movie is… (link)

11. A long solenoid has ## n=500 \, turns/meter ## and has a DC current ## I=+1.0 ## amperes.  The magnetic field ## B=n \mu_o I =6.28 E-4 \, Weber/m^2## inside the solenoid.  A long cylindrical permanent magnet has (approximately) uniform magnetization pointing along the z-axis.  Given the magnetic field strength ## B=1.0 \hat{z} \, Weber/m^2 ## inside the permanent magnet (i.e. in the interior,  away from the endfaces),  what is the magnetic surface current per unit length ## K_m ## on the outer surface of the cylindrical magnet? (Link)

12. What computer programming language is closest to machine language? (Link)

13. What kind of scientific data collection does this Insight discuss at boat ramps? (Link)

14. What happens to an object that free-falls radially into a Schwarzschild black hole? (Link)

15. What mathematician died in a duel? (Link)

16. If we play a 36Hz tone and a 48Hz tone together, how many ‘beats’ per second will we hear? (Link)

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4 replies
1. Greg Bernhardt says:

Added another question from [USER=372855]@stevendaryl[/USER]'s Insight

2. Greg Bernhardt says:

Added another question from [USER=197831]@PeterDonis[/USER]'s Insight