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Physics: Motion. The Insanity Begins!!! ( dum dum dum ) Mr. Fox’s Science Class. Motion. Something is in motion when its distance from another object is changing. But that doesn’t mean it’s constantly moving (OMG WHAT?)
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Physics: Motion The Insanity Begins!!! (dumdumdum) Mr. Fox’s Science Class
Motion • Something is in motion when its distance from another object is changing. • But that doesn’t mean it’s constantly moving (OMG WHAT?) • Reference Point – place or object used for comparison to determine if something is in motion. • You are in motion if your distance is changing relative to a reference point.
Has your brain exploded yet? • What does that all mean? (you don’t have to write this.) • Does it hurt?
Don’t Forget • We measure using the metric system. • Distance is measured in meters • Time is measured in seconds, minutes, or hours. • Naked Number are now wrong answers! No label on a number, no credit for the work!
Speed!! • The distance of an object travels in one unit of time. • Unit = m/s km/h cm/s….. etc.
Examples • A horse travels 21 meters in 3 seconds. How fast is the horse traveling? • A car drives on the Thruway from Kingston to Albany in about 64 minutes. It travels about 78.875 km. How fast was the car traveling? • A car is traveling at 72.34 km/h for 4 hours. How far did the car travel? • Michael Johnson is one of the fastest men on Earth with an average speed of 10.325 m/s. How long would it take him to run 200 m?
Average Speed • It is done a little different. • A cyclist travels 32 km during the first 2 hours, and then 13 km for the next hour. What is the average speed. • I hardly ask these.
Velocity • The speed and direction of an object’s motion. • Speed in a given direction! You don’t know an objects velocity if you don’t know the direction! • Tough One: If a person runs around a track, that is 1,000 meters (the track is round.) in 100 seconds, what is the runners velocity?
Acceleration • The rate at which velocity changes. • Acceleration is increasing speed, decreasing speed, or changing direction. • Decreasing speed = - (negative) acceleration! (it is possible!!!!!)
Acceleration Formula Units: m/s/s or m/s2
Practice questions • A car is running around the track at a slow speed of 96km/h. The green flag for the race drops and the car speeds up to 321km/h in about 25seconds. What is the cars acceleration? • A train needs to slow down to make stop for the station. The train is traveling at 150km/h. It will take the train 0.083 hours to stop. What is the trains acceleration?
Gravity? • Acceleration due to gravity is 9.80665 m/s2 (approx. 32.174 ft/s2 at sea level!) • Meaning that if you were to kick Mr. Fox out of a plane, he would keep falling 9.8o665 m/s faster every second! • 1 second speed equals 9.80665, 2 seconds twice that, 3 seconds… well you don’t want to think about it.
More Practice • A plane taking off from Newark airport goes from resting to 268.224 m/s in 300 seconds. What is the planes acceleration? • That same plane flies from Newark to LAX. It flies a total of 3918.66km in 6 hours. What was the speed of the plane? • A fight breaks out in the plane between CCand Mr. Fox. CCis able to throw Mr. Fox out of the plane. Mr. Fox reaches a speed of 274m/s while falling. He hits the ground in 30 seconds. What is his acceleration?