# SI units,scientific notation and too many other questions to tag

Submitted by Anonymous (not verified) on Mon, 09/01/2008 - 21:10

I'm in college and this is not a homework is just a review of the 1st chapter that our teacher gave us to see how we are doing and will not be graded, this is an intro course and I try to answer all of them the best i could and If I'm wrong please correct me, thanks

The ones in Bold are my answers.

1) Below is a list of physical properties and the fundamental unit in the SI system to measure each.
Which unit is not correct fundamental unit for the property?

(A) temperature        Kelvin
(B) lenght                meter
(C) mass                gram

2) Below is a list of common prefixes used in the SI and metric systems. Included with each is an abbreviation and meaning. Which set contains an error?

(A) mega-  M  10^-6
(B) nano-    n    10^-9
(C) deci-    d    10^-1

3) Which of the following is equivalent to 10cm?

(A) 1 m
(B) 1000 um
(C) 100 mm
(D) 100 nm

4) A bug travels at a speed of 1 cm/s. The notation cm/s could also be written as:
(*) means a dot in the middle but I didn't know how to do it.

(A) cm * s
(B) cm^-1 * s
(C) cm^-1 * s^-1
(D) cm * s^-1

5) Which of the following numbers has 4 significant figures?

(A) 0.43980
(B) 0.0430
(C) 0.04309

6) The sum 2.834 + 5.71520 + 2.12 + 178.1 + 250.2619 expressed to the proper number of significant figures is:

(A) 439.0
(B) 439.03 I think is this one because significant figures have 2 decimals, not sure.
(C) 439.031

7) The answer to the following calculation, rounded to the proper number of significant digits, is:
23.413 g divided by (2.15cm x 1.1 cm x 3.73 cm)

(A) 3.0 g/cm^3
(B) 2.654 g/cm^3
(C) 2.7 g/cm^3
(D) 2.7 g.cm^3

8) What is the height in centimeters of a person who is 5 feet 10 inches tall?
(x) means times and (/) means division

(A) 1.8 x 10^2 cm
(B) 3.6 x 10^-2 cm
(C) 1.5 x 10^2 cm  I did 70in x 1 x 12in/1ft x 1cm/1 x 10^-2m, got 1.44,  ???

9) It requires 2.26 x 10^3 J  to boil 1 g H2O. How many kJ are required to boil 1.00 lb H2O?

I don't know how to figure this one out i tried but i didn't get any closer.  >:(
(A) 1030 kJ
(B) 4.98 kJ
(C) 2260 kJ

10) At 25 degrees Celsius, one milli-liter of mercury has a mass of 13.6 grams. How many liters of mercury are required to have a mass of 500kg of mercury?

(A) 25.2 L
(B) 42.1 L
(C) 36.8 L I Multiply 13.6 X 36.8 = 500kg I don't know if I use the right logic.

1) I believe the fundamental unit of mass is the kg

5) Which of the following numbers has 4 significant figures?

(A) 0.43980
(B) 0.0430
(C) 0.04309
Check out the Atlantic-Pacific Rule (http://www.belmont.k12.ma.us/class_pages/kmcgrane/index_files/Ch%201%20measurement,%20SF%20notes%202006%20stud%20version.pdf)

6) The sum 2.834 + 5.71520 + 2.12 + 178.1 + 250.2619 expressed to the proper number of significant figures is:

(A) 439.0
(B) 439.03 Your answer can only have the same number of decimal places as the least precise piece of data, in this case 2.12.
(C) 439.031

8) What is the height in centimeters of a person who is 5 feet 10 inches tall?
(x) means times and (/) means division

(A) 1.8 x 10^2 cm
(B) 3.6 x 10^-2 cm
(C) 1.5 x 10^2 cm  I did 70in x 1 x 12in/1ft x 1cm/1 x 10^-2m, got 1.44,

Should be 70 in x (2.50 cm/ 1 in) = 178 cm = 1. x 10^2 cm

9) It requires 2.26 x 10^3 J  to boil 1 g H2O. How many kJ are required to boil 1.00 lb H2O?

I don't know how to figure this one out i tried but i didn't get any closer.
(A) 1030 kJ
(B) 4.98 kJ
(C) 2260 kJ

Convert 1b to grams:
1 lb  x  1 kg/2.2 lb  x  1000 g/kg
Multiply the number of grams times 2.26 x 10^3 J/g.

10) At 25 degrees Celsius, one milli-liter of mercury has a mass of 13.6 grams. How many liters of mercury are required to have a mass of 500kg of mercury?

(A) 25.2 L
(B) 42.1 L
(C) 36.8 L I Multiply 13.6 X 36.8 = 500kg I don't know if I use the right logic.  Nope

500 kg x 1000 g/ 1kg  =  500,000 g

Now convert grams to mL

500,000g  x  1 mL / 13.6 g =  _______ mL

Convert mL to Liters:
______ mL  x  1 L / 1000mL =    ______ L

Awesome your examples Helped A lot, Thanks :)