ElectricPavlov

"If this is an emergency, please sign off and dial 9-1-1 "       LOL

Left off units but Mercury melts at -39 F would be close to correct......but this is NOT absolute temperature.

-39 f = 233.706 K 

233.706 x 4 K = melting point of Krypton = 233.706*4 = 934.824 K =1223 degrees F

Which makes no sense as krypton is a gas at MUCH lower temps than this......so I suspect that the question has some incorrect info in it.

Melting point of Mercury is actually -37.89 F = 234.32 K

Melting point  of Krypton is acually -251.2 F =115.82 K  

SO the melting point of mercury is actually approx TWICE that of Krypton , not 1/4

Each day the problems work double so it is a power of two formula

2^5 = 1/3 x     where x is the number of problems

solve for x = 96

at 5 days they will have completed 32 of the problems.... the NEXT day they will complete 64 problems for a total of 32 +64 = 96 problems.    SO they need ONE more day for a total of 6 days.

36/15 x 20 =36/15*20 = 48 ?     

CORRECTION: That last line SHOULD read;

Side length x Side length   reduces to

(sidelength)^2   for a SQUARE

D'Oh!  

When you have a WIRE conductor moving in a magnetic field the electrons gather at on end creating a net NEGATIVE charge at that end and a net POSITIVE charge at the other end.   No CURRENT will flow unless a circuit load is connected to the ends outside of the field ....this is how our electricity is generated and then used.     With a p-type semiconductor, the process isn't really different....the POSITIVE charges will gather at one side and there will be a equal NEGATIVE charge at the other side .   If you connect a conductor load to the sides, an electron will leave the NEGATIVE end....this creates a 'hole' which will migrate to the other side......at the SAME time this eletron leaves via the condutor another electron ENTERS on the POSITIVE hole side.....this 'fills a hole' so to speak...and this electron will then migrate through the substrate to the negative side to be with his electron buddies filling holes and jumping all of the way.    Not all of the holes and electrons will gather at the sides...thee is always some available throughout the substrate to do this.

This might help with your RHR question:

http://physicsed.buffalostate.edu/SeatExpts/resource/rhr/rhr.htm

Square area = side length X side length     since it IS a square the side lengths are all equal and this becomes

Square area = 2 x side length

That IS the standard form for the equation of a line in the form   y = mx +b    where m = slope (-1/2) and b is the y-axis  intercept (10)...

If all of the grades are weighted equally and you have  100 , 100 and 0 . your average is

(100+100+0 )/3 = 66.67    either a 'D' or an 'E' or 'F' depending on how your grading scale is set .

I think the answer to this question is :   ∅     (null)