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Showing posts from August, 2017

Notes on notes.

Some thoughts on how to take notes in physics.  This is all personal preference, but it has served me well. 1.  Use a bound notebook, ideally with quad-paper.  Spiral-bound notebooks fall apart and binders are cumbersome (and the pages fall out before long).  Bound notebooks keep you "honest." 2.  Use a new page for each new class and/or topic. 3.  Write on only side of the page - it makes it easier to read, particularly if you use pen (which can bleed through to the other side). 4.  Give each new page a heading and date. 5.  Use color to highlight central concepts and/or put boxes around important ideas or equations. 6.  Draw pictures that represent the problem - label relevant things in the diagram. 7.  Don't use a laptop to take notes.  You spend too much time getting down trivial details and will inevitably miss something critical.  It is also way too tedious to include equations, pictures, graphs, calculations and anything that really dem

SI Units!

Some comments on standards. We generally use SI units in physics. To inform you: Mass is measured based on a kilogram (kg) standard. Length (or displacement or position) is based on a meter (m) standard. Time is based on a second (s) standard. How do we get these standards? Length - meter (m) - originally 1 ten-millionth the distance from north pole (of Earth) to equator - then a distance between two fine lines engraved on a platinum-iridium bar - (1960): 1,650,763.73 wavelengths of a particular orange-red light emitted by atoms of Kr-86 in a gas discharge tube - (1983, current standard): the length of path traveled by light during a time interval of 1/299,792,458 seconds That is, the speed of light is 299,792,458 m/s. This is the fastest speed that exists. Why this is is quite a subtle thing. Short answer: the only things that can travel that fast aren't "things" at all, but rather massless electromagnetic radiation. Low-mass things (particles) can travel

Welcome to Physics!

Physics Sean Lally, teacher 2017 – 2018 A and C blocks Room 360 Office:  342 (across from student mailboxes) Availability:  X blocks, 3 PM slally@parkschool.net 410-339-4104 Hello there, physics phriends!  Welcome to a new school year and your new favorite class, Physics, with your humble host, Sean Lally. I am thrilled to be sharing some of the big ideas of physics with you this term.  We will draw our class content from the following areas: Mechanics – motion (kinematics), forces (dynamics), gravitation, energy Waves – mechanical waves (like sound) and electromagnetic waves (like light), optics Electricity & Magnetism – static electricity, circuits, magnetism, electromagnetism, induction Our first semester will find us largely delving into mechanics, first with a discussion on units and velocity.  After this, we will discuss acceleration, as a preparation to a big section on forces. On grades: There will be several opportunities fo