Solutions to Physics I H Dimensional Analysis Homework 1

Solutions to Physics I H Dimensional Analysis Homework
1.) Convert 7.35 km to:
a) meters
103 π‘š = 1 π‘˜π‘š
103 π‘š
7.35 π‘˜π‘š π‘₯
= 7.35π‘₯103 π‘š
1 π‘˜π‘š
b) centimeters
1 π‘š = 102 π‘π‘š
7.35 π‘˜π‘š π‘₯
103 π‘š 102 π‘π‘š
π‘₯
= 7.35π‘₯105 π‘π‘š
1 π‘˜π‘š
1π‘š
c) megameters
106 π‘š = 1 π‘€π‘š
7.35 π‘˜π‘š π‘₯
103 π‘š 1 π‘€π‘š
π‘₯
= 7.35π‘₯10βˆ’3 π‘€π‘š
1 π‘˜π‘š 106 π‘š
d) picometers
1 π‘š = 1012 π‘π‘š
103 π‘š 1012 π‘π‘š
7.35 π‘˜π‘š π‘₯
π‘₯
= 7.35 π‘₯1015 π‘π‘š
1 π‘˜π‘š
1π‘š
2. Convert 1.750 terabytes to megabytes
1.750 𝑇𝐡 π‘₯
106 𝑀𝐡
= 1.750π‘₯106 𝑀𝐡
1 𝑇𝐡
3. Convert 8.62 km/s the mi/h
8.62
π‘˜π‘š
1 π‘šπ‘–
3600 𝑠
π‘₯
π‘₯
= 19,274 π‘šπ‘– β„β„Ž = 1.93π‘₯105 π‘šπ‘–/β„Ž
𝑠 1.61 π‘˜π‘š
1β„Ž
4. A baby born in the U.S. weighs 3.295 kg according to the scale in the birthing room. Convert
this to pounds and ounces so you can tell the grandparents how much the baby weighed.
3.295 π‘˜π‘” π‘₯
2.20 𝑙𝑏
= 7.249 𝑙𝑏
1 π‘˜π‘”
0.249 𝑙𝑏 π‘₯
16 π‘œπ‘§
= 3.984 π‘œπ‘§
1 𝑙𝑏
∴, 3.295 π‘˜π‘” = 7 𝑙𝑏 3.98 π‘œπ‘§
5. A child requires a 5 mL dose of medicine each day. How many days would a gallon of this
medicine last?
5
π‘šπΏ
1𝐿
1 π‘”π‘Žπ‘™
π‘₯
π‘₯
= 0.0013 π‘”π‘Žπ‘™ β„π‘‘π‘Žπ‘¦
π‘‘π‘Žπ‘¦ 1000 π‘šπΏ 3.79 𝐿
Taking the inverse of this yields:
758 π‘‘π‘Žπ‘¦π‘ β„π‘”π‘Žπ‘™
6. How many years old are you if you have lived 1 billion seconds?
109 𝑠 π‘₯
1 β„Žπ‘Ÿ 1 π‘‘π‘Žπ‘¦
1 π‘¦π‘’π‘Žπ‘Ÿ
π‘₯
π‘₯
= 31.7 π‘¦π‘’π‘Žπ‘Ÿπ‘ 
3600 𝑠 24 β„Žπ‘Ÿ 365 π‘‘π‘Žπ‘¦π‘ 
7. 1 milliliter of ink can print 50 pages of text. If you had 100 gallons of ink then how many
pages could you print?
100 π‘”π‘Žπ‘™ π‘₯
3.79 𝐿 1000 π‘šπΏ
π‘₯
= 379,000 π‘šπΏ
1 π‘”π‘Žπ‘™
1𝐿
379,000 π‘šπΏ π‘₯
50 π‘π‘Žπ‘”π‘’π‘ 
= 1.9π‘₯107 π‘π‘Žπ‘”π‘’π‘ 
1 π‘šπΏ
8. A clerk can sort 375 sheets per hour. If there are 225 sheets in an inch, how long will it take
her to file 125 inches of loose sheets?
125 𝑖𝑛 π‘₯
225 π‘ β„Žπ‘’π‘’π‘‘π‘ 
= 28,125 π‘ β„Žπ‘’π‘’π‘‘π‘ 
1 𝑖𝑛
28,125 π‘ β„Žπ‘’π‘’π‘‘π‘  π‘₯
1 β„Žπ‘Ÿ
= 75 β„Žπ‘œπ‘’π‘Ÿπ‘ 
375 π‘ β„Žπ‘’π‘’π‘‘π‘