PHYS 100 Chapter Notes - Chapter 1.4: Significant Figures, International System Of Units, Kilogram

• School: Simon Fraser University
• Department: Physics
• Course: PHYS 100
• Professor: Firuz Demir

Document Summary

Significant figures: a digit that is reliably known: 6. 2 has 2 significant figures, 34. 62 has 4 significant figures. When multiplying, dividing, or taking a square root the answer should match the significant figures of the least precisely known number in the question: 3. 73*5. 7=21. When adding or subtracting numbers, the number of decimal places in the answer should match the smallest number of decimal places in any of the numbers in the calculation: 18. 54+106. 6=125. 1. S(cid:272)ie(cid:374)tists use a syste(cid:373) of u(cid:374)its (cid:272)alled le syste(cid:373)e i(cid:374)ter(cid:374)atio(cid:374)ale d"u(cid:374)ites=>si u(cid:374)its. Common si units: time=>second=>s, length=>meter=>m, mass=>kilogram=>kg. Common prefixes: mega-=>m=>10^6, kilo-=>k=>10^3, centi=>c=>10^-2, milli=>m=>10^-3, micro=> =>10^-6, nano=>n=>10^-9. Order-of-magnitude estimate: a one significant-figure estimate or calculation. Vectors and motion: a first look (pg 16) Scalar quantity: a physical quantity described by a single number (with a unit). Vector quantity: a quantity that has both a size and a direction. Magnitude: the size or length of a vector.