Transcript Document

Motion
• Written Quiz
• More on proportionality
• Motion Diagrams in 1-D
Intro
General Quiz rules:
• Start when you are told to
• Stop writing as soon as you are told to
• Make sure that the TA can figure out which
answer you circled
• Turn your paper over as soon as you are finished
• If you are not finished, look ONLY at your own
paper
PRQ
This Quiz:
• You have 10 minutes
• I will give you a 30 second warning
• Please be sure to include your name AND
student number!
Quiz Answers
Proportionality
- another way
If x  t2  x = C t2
Some constant
You can use initial conditions to find the value of
the constant ‘C’. Once you do, you can use the
equation to predict future results.
QQ3 Prop
Worked Example
A spring compressed by a force of 5N is compressed
by 10cm. If a force of 20N is used, how far would
the spring compress, given that for a simple spring:
F  x, where F is the force and x the compression.
(A) 5 cm
(B) 10 cm
(C) 20 cm
(D) 30 cm
(E) 40 cm
Motion Diagrams
• Motions Diagrams help give information about
position as a function of time
• The positions in a Motion Diagram are always
shown at equal time intervals
Like Movie Frames
But Overlaid
Like Movie Frames
Constant Velocity Case:
a= ?
x
t
Demo
Extra
QQ
Quick Quiz 5X - difficult
Draw a motion diagram for a bouncing ball.
Start the diagram when the ball is released,
and end the diagram when it gets back to the
top of its bounce.
Do for next class:

• Read: sections 1.3  pay special attention to  r
• Other preparation: WebCT Vectors/Scalars forum