September 23

     We started the class by marking the two homework worksheets:
"Even more UNITARY RATES" (white one) and "Review WS-scientific Notation" (brown one).
     It was basically a review of what we have been learning combined. There wasn't any new materials covered today.
     Afterwards, we had a practice quiz on Chapter 1-"Unit Conversions with Quantities" and marked it together. Examples of the questions are:

1. Convert 0.845 mol into millimoles.
    0.845mol  x 1000 = 845 millimoles.
2. Convert the speed of sound in air(1234km/hr) to cm/ms.
    1234km x 1/3600 x 1/1000 x 100000 = 34.3cm/ms

There was also an interesting bonus question:
A farmer need to wrap a gift of 2 horses where 3 horses = 5 cows, 1 cow = 5 hogs, 3 hogs = 5 goats, 1 goat = 9 chickens. How would the farmer pay for the 2 horses with chickens?

Answer = 250 chickens!

Lastly, for homework, make sure you are prepared for the Chapter 1 (unit conversion) quiz on Monday!!
Remember to MEMORIZE the SI prefixes and Conversion factors Table! (at least top 3 rows)
Practice Questions you can do:
1. a). 1mm -> km
    b) 56 L -> mL
    c) 45.2 dm -> cm
2. A dog barks 5 times per minutes. How many times will the dog bark in 7 minutes?
3. There are 40 weeks in a school year. Hwo many seconds are there in this time?
4. A human adult has on average 2 square feet of skin. There are about 75 mites per mm2 on your skin. Each mite eats 2 ug of dead skin per day. How many kg of skin gets eaten by mites per year? (note: 1foot = 30.48cm)