Free MIT online qualification...

anybody have any idea what they mean by "more advanced mathematics coming up in the second semester"?

Had a look at the course material yesterday. Fairly intensive for someone like me who has been out of school for a long time but plan to give it my best shot. First homework is due on the 16th.

I've enrolled in this course and am impressed with it so far.

Seems like MIT have put a lot of work into this.

I will be posting on this thread as I go along. Currently going through Week 1 lectures.

You handed in your homework yet?

i'm stuck on the last question about the heaters that were incorrectly fitted, can get answer, Help!!!

Tigger wrote: »

work out the resistance of a heater
then use kirchoffs laws to work the total resistance in the circut

OK, finally have wk 1 done, Thanks for the tip Tigger, but it still took alot of time to figure out, getting worried about what's ahead!!!, Have you done wk2?

I'm beat on H2P1: VOLTAGE-DIVIDER DESIGN, spent hours today at it, Can someone help?

Tigger wrote: »

Voltage dividers use a sub circuit with resistors of a certain ratio to step down a voltage by that ratio

You need to make the voltage 1.5v
So a ratio of 3:1 will work

6/4*1=1.5
6/4*3=4.5

So you split the voltage 1.5 : 4.5

Or 3:1
http://en.m.wikipedia.org/wiki/Voltage_divider

I must be doing somthing wrong somewhere, My Vin 40, Vout 14, cant figure out the ohms and Vmax Vmin

The resistances of commercially-available discrete resistors are restricted to particular sets. For example, the available values of resistors with 10% tolerance are selections from the E12 set multiplied by a power of ten from 10^0 through 10^5. The E12 set is
E12={10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82}
Thus, you can buy 10% resistors with a nominal resistance of 330Ω or 33kΩ, but not 350Ω.
The "tolerance" means that if you buy a 10% 390Ω resistor you can be sure that its resistance is between 351Ω and 429Ω.
In this problem we need to choose 10% resistors to make a voltage divider that meets a given specification.


We are given an input voltage Vin=40.0V, and we need to provide an open-circuit output voltage of Vout≈14.0V. An additional requirement is that the Thevenin resistance as seen from the output terminals is between 10kΩ and 30kΩ. Assume first that the resistors have their nominal resistance. Come up with resistors R1 and R2 such that the division ratio Vout/Vin is within 10% of the requirement.
Of course, the resistances you chose are just nominal. Given that they are only guaranteed to have resistances within 10% of the nominal value, what is the largest and smallest value that Vout may have?

you have started late so you will have missed the first two weeks dead lines