Chapter 2
Motion along a (straight) line
1-D motion
Position and Displacement
Consider object (thing) moving along straight line
Choose x axis / line
Choose positive direction (x increasing)
Choose o
Projectile Motion
Trajectory is a parabola (Pg 69)
vix = vicos, viy = visin
vy = 0 at max height, but
vx = constant
Range defined as coming back to initial height y = 0
Angle of trajectory
at any poi
Class 4, 9/5
Sections 001 & 004 (David Bowen)
Back Channel http:/TodaysMeet.com/Framed
WebAssign
Exams will be based on credit and non-credit WebAssign
problems, transformed
Many Non-Credit problems a
Free Fall
Free fall refers to an object released and falling all by itself, just
by gravity (e.g. neglecting air resistance)
By experiment, free fall occurs with a constant downward
acceleration of 9
Chapter 3 - Vectors
Wow is this important!
Chapter 3
Motion in 2D: Vectors
Define a new type of thing a vector, has both magnitude (+ve
value, units) and direction
Algebraic symbol: bold with arrow a
Constant Acceleration
Intro: what is acceleration?
Consider an object moving along a straight line
Object anything
Choose an x axis (like a ruler) along the line
Axis direction: direction in which x
Chpt 4: Force and Newtons Laws
From 1687, tested continuously since (passed!)
Three Laws, start with second
About me most important info up front
N2:
applies to an object (thing)
m = mass (quantity o
Acceleration
As with velocity, define average (aav,x) and instantaneous (ax)
(instantaneous) acceleration ax
Average acceleration aav,x vx/t
ax = slope of vx-t plot, rate of change of vx
ax positive,
Example 1
A bullet starts from rest and accelerates at a constant rate down
a gun barrel 0.8 m long and emerges with a velocity of 1000
m/s.
Find its acceleration.
How long does the trip down the gun
Example: A mass m is hung by
an ideal rope from a frictionless
pulley as in the sketch to the right.
Find the net force on the mass.
Fnet = 2T up + mg down
Example: Bird on a Wire
A bird with mass 1.