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Why go into physics? . Go to www.physics.org Find 3 areas that interest you List 2 jobs that you could have in that area Google 1 of the jobs and try and find out how much that job makes. Physics effects every moment of your life! . ____________________ ____________________
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Why go into physics? • Go to www.physics.org • Find 3 areas that interest you • List 2 jobs that you could have in that area • Google 1 of the jobs and try and find out how much that job makes
Physics effects every moment of your life! • ____________________ • ____________________ • ____________________ • ____________________ • ____________________
CH. 2 Motion Keep on truckin
What is motion? • Motion is a change of position of an object. • A reference point must be specified in order to determine an object's position
What is Speed? • Rate—any change over time • Speed—the distance an object travels per unit of time. fastest
The Comic Book of Science Graphs! Speed= distance time graphs • The slope of a line (steepness) on a distance-time graph is equal to the speed. • Shallow slope is slower than steep slope
Draw this on your paper! Y-axis faster slower Distance (meters) Standing still X-axis Time (seconds)
Distance Time Graphs • What information is recorded on the x-axis? • How many minutes does each line represent? • In what units is distance measured on the graph? • The graphs represent three swimmers, What does the slope of the lines tell you about the swimmers?
Which swimmer swam the fastest? • Which swimmer stopped for 10 minutes? • How far did the blue swimmer travel in 15 minutes? • What is the difference in distance traveled between the red and green swimmer?
Warm-up 1/31/11 • Review questions: What is one thing that is good for the brain to learn? • Teach the teacher questions: What is your favorite dessert? Do you have a cell phone? Does your cell phone have a camera?
What are the fastest animals (mph)? • Cheetah 70 • Pronghorn antelope 61 • Lion 50 • Thomson's gazelle 50 • Wildebeest 50 • Springbok 50 • Quarter horse 47.5 Cape hunting dog 45 • Elk 45 • Coyote 43
The real world graphing… • The Band is on the Field!
D S T divide multiply Calculating Speed • The speed of an object can be calculated from this equation: • Speed = Distance Time • S=D/T • When working equations • Write the formula • Plug in the values for each known • Calculate the answer • Write the answer and a unit
Average & Instantaneous Speed • Average speed—the total distance traveled divided by the total time of travel. • Instantaneous speed—the speed at a given point in time.
Physics To Win It Tada
Velocity • Speed describes only how fast something is moving. • Velocity—includes the speed of an object AND the direction of its motion
Example: • Example: a race car has a constant speed of 100km/hr around an oval track. • The speed remains constant, but the velocity changes.
Acceleration • Acceleration—the rate of change of velocity. • The change in velocity over time • acceleration = change in velocity time • When something speeds up, it has a positive acceleration • When something slows down, it has a negative acceleration.
Application of speed, velocity, and acceleration • Sports Science