# Chapter 11 ```Chapter 11
Motion
Sec. 11.1
Frame of reference
A system of objects that are not
moving with respect to one another
Used in order to see motion
Describes motion accurately
Relative Motion
Movement in relation to a frame of
reference
Ex. People in a car appear to be
moving to the people on the side of
But when people in the car look at
one another they do not seem to be
moving at all.
Interactive practice with frame of reference
http://www.amnh.org/learn/pd/physical_science/week2/frame_referen
ce.html
http://www.physics-chemistry-interactive-flashanimation.com/mechanics_forces_gravitation_energy_
interactive/frame_of_reference_motion_child_ball_trai
n.htm
Video on frame of reference
OLD SCHOOL
http://archive.org/details/frames_of
_reference
Distance
Length of a path between 2 points
The SI unit for distance is the meter
Vs.
Displacement
Length of straight line from start to
end
Vector
Quantity that has magnitude (size,
length or amount) and direction
Arrows represent vectors (they show
a numerical value and a direction)
Resultant Vector
Vector sum of 2 or more
vectors
Points directly from the
starting point to the
ending point
Go over this with the class before the activity
Distance vs displacement
http://physics.info/displacement/
Quick Lab
Turn to page 330
Obtain a sheet of graph paper and a
ruler
Follow the direction for the quick lab
Turn your lab in 1paper with two
names on it.
Sec 11.2 speed
Ratio of the distance an object
moves to the amount of time the
object moves
Write formula page 333
Average speed- entire trip
Instantaneous speed- measured
at a particular instant (Ex.
Speedometer)
Average Speed
Average Speed = Total Distance
Total Time
V`= d
t
http://www.nbclearn.com/nfl/cuecard/5
0770
Average Speed
Total distance/total time
Ex. Drove 50 m in 28 sec, drove
200 m in 180 sec, stopped for 50
sec, drove 100 m in 100 sec.
What is average speed?
50 m +200m +0 m + 100 m=350m
28 s + 180 s + 50 s + 100 s=358s
= 350 m /358 s = _0.98__ m/s
More practice
Let’s work through math
skills/practice page 333 together
Copy steps into your notes from
page 333
More v=d/t
Icurio activity
http://www.icurio.com/goExternal?np
=/templates/sections/external/extern
al.ftl&amp;pp=/templates/sections/frame
work/error.ftl&amp;evlCode=272477&amp;prod
uctName=icurio&amp;al=High
Graphing Motion
Distance-Time graph
The slope of the line on the graph is the
Slope=rise
run
Book page 334
Let’s read through this and look at the
bottom of the page
A steeper slope on a distance time graph
indicates a higher
.
You tube Moving man
2ve5yucNPQ
Click the link below to do the interactive
http://zonalandeducation.com/mstm/
physics/mechanics/kinematics/xvaVs
Time/xVsTime.html
Click this link next and do this interactive second
http://www.mangahigh.com/en/math
s_games/shape/speed_distance_time
/distancetime_graphs
Practice with graphs
http://www.thatquiz.org/tq/previewt
est?C/F/D/L/34921292529116
How does a speedometer work?
It measures distance (the number of
times the tires turn) and speed
( their rate of turning)
Velocity
Description of both speed and
direction of motion
Velocity is a vector
A change in speed, direction, or
both will result in a change of
velocity
Discovery ed interactive
http://app.discoveryeducation.com/
http://www.physicsclassroom.com/cl
ass/vectors/u3l1b.cfm
Sec.11.3
Acceleration
The rate at which velocity changes
Changes speed, direction, or both
Acceleration=change in velocity
total time
a= (vf-vi)
t
Extra Help
To rearrange the equation to solve
for other variables, especially vi or vf
1.multiply both side of the equation
by t
2.cancel the t/t on the right side of
the equation
3.add vi to both sides of the equation
Practice this
1. a sprinter accelerates from the starting
block to a speed of 8.0 m/s in 4.0 s. What
is the magnitude of the sprinters
acceleration?
(2.0 m/s2)
2. a car is traveling at 14 m/s. Stepping
on the gas pedal causes the car to
accelerate at 2.0 m/s2. How long does the
driver have to step on the pedal to reach a
speed of 18 m/s?
(2.0 s)
Free fall
http://www.regentsprep.org/Regents/physics/phys01/accgravi/index.htm
Click and go through the link with the class.
Acceleration due to change in
The movement of an object
toward Earth solely because of
gravity
Constant Acceleration
velocity
Changes the same
amount each second
Instantaneous Acceleration
How fast a velocity
is changing at a
specific instant
Graphs of Accelerated Motion
Speed-time graph
The slope of the line on the graph is the
acceleration
Constant acceleration is demonstrated
with a straight line or linear graph
Accelerated motion is demonstrated with
a curved line or nonlinear graph
ex. A car at a stop light accelerates
(when green) to 15m/s in 5 sec.
What was their acceleration?
Final
= 15 m/s
Initial
= 0 m/s
Time = 5 sec
a= 15 – 0/5 = 3 m/s2
Ex. A car traveling 30 m/s comes to
a stop in 3 sec. What was their
acceleration?
Final
Initial
= 0 m/s
= 30 m/s
Time = 3 sec
a = 0 –30/3 -10m/s2
negative slowing down
Let’s practice
Page 346
Math skills copy the example
Math Practice