Back Link
to Step 1 and 2 Back to
Dimensional Analysis Main Menu
Apply the unit analysis method of problem solving to each of the following
(setup statement 1 pt, unit analysis setup 3 pts,
answer 1 pt with its proper unit) (If greater than
three significant figures round off to three significant figures):
Problem #1
How many karats is a diamond weighing 234.2 mg?
(One karat = 0.200 g)
____???____ karat = 234.2 mg
Given Unit Factors
|
Unit Factors Not Given
|
|
||||||||||
|
??? karat |
= |
234.2 mg |
X |
1 g |
X |
1 karat |
= |
1.17 karat |
|
|
|
|
|
|
||||||
1 |
1 |
1000 mg |
0.200 g |
1 |
||||||
|
Problem #2
Insurance statistics state that a person loses 8 minutes of average
life for each cigarette smoked. If there are 20 cigarettes in a pack and the
average cost of cigarette is $4.50 per pack over the next 15 years, how many
years of average life would a person lose for smoking 1.5 packs a day for 15
years?
____???____ yrlifelost = 15 yrsmoking
Given Unit Factors
|
Unit Factors Not Given
|
The important bridge between life lost and smoking is the 8 minutes lost = 1 cig smoked Unit Factor.
|
||||||||||||||||||||
|
??? yrlifelost |
= |
15 yrsmok |
X |
365 daysmok |
X |
1.5 pack |
X |
20 cig |
X |
8 minlost |
X |
1 hrlost |
X |
1 daylost |
X |
1 yrlost |
= |
2.5 yrlifelost
|
|
|
|
|
|
|
|
|
|
|
|
|||||||||||
1 |
1 |
1 yrsmok |
1 daysmok |
1 pack |
1 cig |
60 minlost |
24 hrlost |
365 daylost |
1 |
|||||||||||
|
1. A quartz rock was cut into a rectangular solid paperweight. IF the paperweight has a mass of 165 g and measures 5.00 cm by 5.00 cm by 25.0 mm, what is its volume in cubic centimeters?
____???____ cm3
= 5.00 cm X 5.00 cm X 25.0 mm
10 mm = 1 cm ;
therefore 25.0 mm = 2.50 cm (all units
must be equal)
Volune = L3 = 5.00 cm X 5.00 cm X 2.50 cm = ____62.5__cm3
2. Calculate the density in g/mL for 10.0 grams of ethyl ether having a volume 14.0 mL.
Density = ____???____ g/m
Density = Mass/Volume = 10.0 g/14.0 mL = 7.14 g/mL
Link to
Step 1 and 2 Back to
Dimensional Analysis Main Menu