Physics - Equations of Motion (Review)

OPENING QUESTION:

Please do this now if you didn't do this previously!

You're lying flat on your back in a field on Fox Island. You shoot a frozen grape directly upwards with an impressive initial velocity of 81.33 m/s (and then quickly roll to the side, you don't want to get splattered by your own grape-- right?)

Without doing any math at all, make a case for the entire time the grape will be in flight

Without doing any math at all, make a case for the velocity of the grape the tiniest fraction of a second before it goes *splat* on the ground next to you.

Now please calculate how high it goes

Now please calculate how long it is in the air in total

Calculate the velocity of the grape just before it hits the ground and compare that to your expectations that you outlined above.

 

LEARNING OBJECTIVES:

  1. I will be able to recite all equations of motion by memory by the end of today's class.
  2. I will be able to perform moderately difficult horizontal motion problems after today's class.
  3. I will be able to perform basic vertical motion problems during today's class.

CALENDAR: 1 Dim Motion Test on Friday

WORDS O' THE DAY:

  • friction - ALWAYS works against motion

FORMULAE OBJECTUS:

    • a = (vf - vi)/(tf - ti) (definition of acceleration)

    • g = 9.81 m/s2 (acceleration an object experience on Earth) ONLY present in vertical motion (Y axis) problems

      0) vt=x (we won't EVER use this for vertical motion--- why not?)

      0) vt=x (this ONLY works in horizontal <x> motion!)

      1) vf = vi +at

      2) vavg = (vi + vf)/2 (this is kinda obvious, and useless)

      3*) xf = xi + vit + 1/2at2

      4*) vf2 - vi2 = 2a∆x

*substitute y for x for vertical problems

WORK O' THE DAY:

We'll work on developing a study plan for FRIDAY's test:

Identify the type of problems that you are MOST comfortable solving

Identify the type of problems that you struggle with

Find sample problems to practice using my website and *assign* yourself work there. Annotate my responses to help your understanding-- that is by way of saying print them out or get them on your screen and write step by step instructions as if you were explaining those to a friend who has yet to take physics.

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Physics Classroom

My answers are on previous lesson plans from last week.

Blue font problems are on a separate days' plan