WarmUp 93013 Your warmup is on your table
Warm-Up 9/30/13 Your warm-up is on your table (Strobe Diagrams) Read the directions to determine velocity. ALSO, for each of the different strobe diagrams, decide if they show � Acceleration � Deceleration � Neither
ACCELERATION SECTION 11/3 Monday 9/30/13
Acceleration is the rate of change of velocity. Can be due to a change in direction or speed, as velocity depends on both!
Calculating Acceleration Equation and Units D = Change = FINAL - INITIAL Dv = Final velocity – Initial velocity
Example Calculation A Cessna Aircraft goes from 0 m/s to 60 m/s in 13 seconds. Calculate the aircraft’s acceleration.
Example Calculation A Cessna Aircraft goes from 0 m/s to 60 m/s in 13 seconds. Calculate the aircraft’s acceleration. 4. 62 m/s/s
The Cessna now decides to land goes from 60 m/s to 0 m/s in 11 s. Calculate the Cessna’s deceleration.
The Cessna now decides to land goes from 60 m/s to 0 m/s in 11 s. Calculate the Cessna’s deceleration. - 5. 45 m/s/s
What the Signs Mean (+ or -) If your answer for acceleration is + � Velocity (speed) is increasing � Slowing down is happening less quickly (like letting up on the brake) If your answer for acceleration is – � Velocity (speed) is decreasing � Speeding up is happening less quickly (quick off the line, and then accelerating slowly)
Graphing Acceleration We can determine acceleration based on velocity-time graphs (distance-time graphs are for determining velocity)
Example What is the acceleration from t=0 s to t=3 s? 60/3= 20 m/s/s What is the acceleration from t=3 s to t=5 s? 0/2 = 0 m/s/s What is the acceleration from t=8 s to t=9 s? 0 -60/1 = -60 m/s/s
Free Fall An object in freefall accelerates vertically toward the earth due to gravity Negative because always DOWNWARD Never stops existing (the value doesn’t account for things like wind resistance)
Free Fall Diagram Velocity= 0 m/s, Acceleration= -9. 8 Bottom Line: Downward acceleration in freefall is always the same!
Your Job Finish the Acceleration worksheet (DUE tomorrow) Please TURN IN: Moving Man Simulation from Friday Tuesday-Thursday we are working on our Unit Project! It is counting as your test for the Motion unit.
- Slides: 15