1. Physics 11 Advanced Mr. Jean February 14th, 2012

2. The plan: Video clip of the day Reminder about Motion Detector Lab Free Fall Motion –Solutions to in class problems 2D motion Introduction to Projectiles 2D motion questions.

3. Reminder: Motion Detector Ranger Lab due at the end of the day. 3:40pm

4. Free Falling Objects: When an object is dropped. –1) There is NO account for air resistance. –2) All Free-Fall objects fall at the same rate –What happens when there is no gravity?

5. A ball is dropped from the top of CN tower which is 440m above ground. The acceleration of gravity is -9.81m/s 2. –A) How long does it take for the ball to hit the ground? –B) At what velocity does it hit the ground?

6. A) How long does it take for the ball to hit the ground?

7. B) At what velocity does it hit the ground?

8. A golf ball is hit straight up with the initial velocity of 50m/s. This action takes place on the moon. The moon’s gravity is -3.4m/s 2. A) How long does it take for the ball to hit the ground if the maximum height is 357.2m? B) How fast does it hit the ground?

9. A) How long does it take for the ball to hit the ground if the maximum height is 357.2m?

10. B) How fast does it hit the ground?

12. 2D Motion

13. x – axis (left & right motion) is determined by the cosine of the angle multiplied by the velocity. v ix = v i *cos(θ) y – axis (up & down motion) is determined by the sine of the angle multiplied by the velocity. V iy = v i *sin(θ)

15. Projectile Motion:

16. Check it out: http://phet.colorado.edu/en/simulation/proj ectile-motionhttp://phet.colorado.edu/en/simulation/proj ectile-motion http://www.addictinggames.com/arcade- games/kittencannon.jsphttp://www.addictinggames.com/arcade- games/kittencannon.jsp

17. Variables: ∆d = distance (m) v y = velocity (m/s) up & down v x = velocity (m/s) left & right g = acceleration due to gravity (-9.81m/s 2 ) –Gravity only influences y-axis!!!! θ = angle in degrees

19. Projectile symmetry:

20. Important Assumptions: No air resistance. Object does not hit anything while in flight. Ground is level unless stated differently. You are on Earth unless stated differently. Gravity field is constant. The object is not moving at light speed.

21. Projectile Motion:

22. Next Day: Wednesday –Constant acceleration problems word problems. –Basic Projectile motion questions Thursday –What are we made of?

23. Free Fall Question An object on Earth starts at rest and free falls for 15seconds. How fast is it falling after 15 seconds? –How fast in Km/h is it falling? How far did it fall after 15 seconds?

24. How fast is it falling?

25. How far did it fall? ∆height?