Dimensional Analysis

1
Dimensional Analysis

• Chemistry

2
Initial and Final Units

• 1. A person has a height of 2.0 meters. What is
  that height in inches?
• Initial unit m Final unit _______
• 2) Blood has a density of 0.05 g/mL. If a
  person lost 0.30 pints of blood at 18C, how many
  ounces of blood would that be?
• Initial pints Final unit _______

3
Steps to Problem Solving

• Read problem
• Write down what you know
• Time symbol and draw a line
• Select conversion factors
• Cancel units and check
• Do math on calculator

4
How many minutes are in 2.5 hours?

• Initial unit
• 2.5 hr
• Conversion Final
• factor unit
• 2.5 hr x 60 min 150 min
• 1 hr
• cancel

5
Learning Check

• A rattlesnake is 2.44 m long. How long is the
  snake in cm?
• 1) 2440 cm
• 2) 244 cm
• 3) 24.4 cm

6
Solution

• A rattlesnake is 2.44 m long. How long is the
  snake in cm?
• 2) 244 cm
• 2.44 m x 100 cm 244 cm
• 1 m

7
Learning Check

• How many seconds are in 1.4 days?
• Unit plan days hr min
  seconds
• 1.4 days x 24 hr x ??
• 1 day

8
Solution CF2

• Unit plan days hr min
  seconds
• 1.4 day x 24 hr x 60 min x 60 sec
• 1 day 1 hr 1 min
• 120000 sec

9
Unit Check

• What is wrong with the following setup?
• 1.4 day x 1 day x 60 min x 60
  sec
• 24 hr 1 hr
  1 min

10
Steps to Problem Solving

• Read problem
• Write Down what you know
• time symbol and draw a line
• Select conversion factors
• Cancel units and check
• Do math on calculator

11
Learning Check

• If the ski pole is 0.000967 km in length, how
  long is the ski pole in mm?

12
Solution

• 0.000967 km x _______

13
Solution

• 0.000967 km x 1000 m
• 1 km

14
Solution

• 0.000967 km x 1000 m x _______
• 1 km

15
Solution

• 0.000967 km x 1000 m x 1000 mm 967
• 1 km 1 m