discussion_problems1

discussion_problems1 - DISCUSSION PROBLEM 1.1: ... answers...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: DISCUSSION PROBLEM 1.1: ... answers ... • Variation of length with temperature? Origin of standardized units: LENGTH • Do you measure to the left-hand edge of the scratch, or the middle or the right-hand edge? • A “fallback” unit of length ... a bar of platinum- iridium with two scratches, exactly 1 meter apart. DISCUSSION PROBLEM 1.1: Can you think of reasons why this may not be such a good standard today? 1 DISCUSSION PROBLEM 1.2: ... answers ... Ordinary numbers. π= circumference [L] = ⇒ dimensionless. diameter [L ] θ= arc length [L] = ⇒ dimensionless. radius [L ] DISCUSSION PROBLEM 1.2: Can you think of any physical quantities that do not have dimension? Note that although θ has no dimension, it does have a unit (radians, degrees)! Specific gravity = weight of an object weight of an equal amount of water ⇒ dimensionless. 2 DISCUSSION PROBLEM 1.3: Population ... answer ... ≈ 300,000,000 Average family ≈ 5 people 1 cup = 8oz In each of 60,000,000 families: DISCUSSION PROBLEM 1.3: Estimate how many quarts of milk (all kinds) are consumed each day at breakfast in the U.S. (a) Four have cereal, or equivalent, 1 cup each = 4 × 1 = 2 cup. 2 2 (b) Two have 2 cups of coffee/tea with milk 1 th cup each = 2 × 2 × 1 = 1 cup. 8 8 2 (c) One drinks milk, = 1 cup. Total consumed by each family ≈ 3 12 cups ≈ 26 oz ∴ Total consumed at breakfast: 26 × 60, 000, 000 = ≈ 50 million quarts! 32 How many cows required? 3 CLASS PROBLEM [1.2]: ... answer B. CLASS PROBLEM [1.2]: Price of gold: 1 ounce of gold ⇒ $1000. What’s the minimum number of men you think would be required to carry a box containing 1M$ worth of gold a distance of 30m? A: ~ 1 man B: ~ 2 men C: ~ 5 men D: ~ 10 men E: more than 10 men Therefore, weight of 1M$ of gold is: 1, 000, 000 = 1000 ounces. 1000 But 16 oz ⇒ 1 pound. ∴ 1M$ weighs : 1000 ≈ 63 pounds. 16 Assume each man can carry ~ 30 → 40 pounds ... ... then it will require ~ 2 men! 4 ...
View Full Document

Ask a homework question - tutors are online