PF Insight Scavenger Hunt 2

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)

 Building up spacetime with quantum entanglement

 Monopoles and the Emergence of Black Hole Entropy

 Gravity and the Nature of Fundamental Particles

 Using Gravitational Lenses to Detect Gravitational Waves

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)

 I only

 II only

 I and II

 II and III

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

 For an adiabatic irreversible process, the change in entropy of the system is zero

 Even for an irreversible process, there are an infinite number of reversible process paths between the initial and final thermodynamic equilibrium states of the system

 You need to evaluate the integral of dq/T for the actual irreversible process path to get the entropy change

 Entropy is not an equilibrium physical property of the materials comprising a system; it depends on the number of irreversible process paths that can be applied to the system

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

 34%

 41%

 58%

 63%

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

 Radioactive nuclei are Jeans unstable if they have more neutrons than protons

 Plasma fluctuations that are Jeans unstable collapse under their own gravity and grow

 Plasma fluctuations that are Jeans unstable oscillate as sound waves

 Jeans instability occurs when pants rip upon bending over

6. The adjoint representation belongs to the theory of (link)

 Gauge Groups

 Lie Algebras

 none of these

 both

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)

 They take energy from the infinite supply of zero-point energy

 They don’t need any energy because their existence is virtual only

 They violate for a short time the conservation of energy

 They rely on the Heisenberg uncertainty relation

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

 field curvature

 coma

 spherical aberration

 distortion

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)

 equal width

 equal perimeter

 equal area

 equal length along the long diagonal

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

 Alien

 Casablanca

 Die Hard

 Ground Hogs Day

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)

 $2.0 E+4$ amperes/meter

 $6.5 E+4$ amperes/meter

 $8.0 E+5$ amperes/meter

 $1.2 E+6$ amperes/meter

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

 assembly

 Fortran

 BASIC

 C

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

 Having boat operators blow in a breathalyzer to measure blood alcohol content

 Writing down vehicle license plates to see what states anglers are from

 Taking water samples for lab analysis of pollutants

 Creel surveys – weighing and measuring anglers’ fish

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

 It slows down as it approaches the horizon, and never actually reaches the horizon.

 It slows down as it approaches the horizon, and stops at the horizon.

 It falls through the horizon and on inward.

 It slows down, stops before it gets to the horizon, and then starts rising again.

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

 Carl Friedrich Gauss

 William Rowan Hamilton

 Joseph-Louis Lagrange

 Evariste Galois

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

 48

 3/4

 12

 36

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