1. Drag racing videohttp://www.youtube.com/watch?v=ryDYYGI1cwg
Speed and Velocity
Drag racing videohttp://

2. JSD- fastest speed through a photo gate
speed describes how quickly something moves.
4 different types of speed
1. instantaneous speed – how fast you are going at a certain point or time.
example: radar gun or speedometer
JSD- fastest speed through a photo gate

3. 2. average speed – looks at the average speed between two points or times.
example: driving from Olympia to Seattle
what we will calculate in this class

4. 3. constant speed – speed stays the same
example: cruise control
the slope of a line is the ratio of the “rise” to the “run”.

5. Peregrine Falcon video
Terminal speed (velocity) – the speed at which an object will stop accelerating when dropped
example: a sky-diver
Peregrine Falcon video

6. They Might be Giants clip
Velocity
velocity is speed with direction (N, S, E, W, up, down, left, right)
positive when moving forward (to the right from an outside observer), and negative when moving backward (to the left to an outside observer).
JSD– walk at constant speed and then change direction

8. Math for Velocity or Speed
v = d/t or v = d ÷ t
v = velocity
d = distance
t = time
Unit of measurement is a distance unit over a time unit
cm/s, m/s, miles/hour, ft/year, miles/hour
if a velocity, should include direction (N, S, E, W)

10. 3-Step Method to Solving Word Problems in Physical Science
Identify what you know (given)
Write down the correct formula to use
Show your work (“plug and chug” using calculator)
Write down answer
Make sure answer has a unit of measurement

11. Example problems
A bike travels 70 meters West in 6.5 seconds. Calculate its velocity.
A car travels a distance of 100 miles in 2.2 hours. Calculate its speed.
Given formula show work answer w/ units
d=70m v=d/t
t=6.5sec
70m/6.5sec
10.8 m/sec West
Given formula show work answer w/ units
d=100 miles v=d/t
t=2.2 hours
100miles/2.2hours
45.5 miles/hour