# lecture06 handout

Published on January 14, 2008

Author: Desiderio

Source: authorstream.com

Two Dimensional Dynamics:  Two Dimensional Dynamics Physics 101: Lecture 06 Today’s lecture will cover Textbook Chapter 4 Exam I Brief Review Thus Far:  Brief Review Thus Far Newton’s Laws of motion Kinematics Dynamics Today we work in 2 Dimensions! 2-Dimensions:  2-Dimensions X and Y are INDEPENDENT! Break 2-D problem into two 1-D problems Position, Velocity and Acceleration:  Position, Velocity and Acceleration Position, Velocity and Acceleration are Vectors! x and y directions are INDEPENDENT! x direction y direction Velocity in Two Dimensions :  Velocity in Two Dimensions 5 m/s 3 m/s A ball is rolling on a horizontal surface at 5 m/s. It then rolls up a ramp at a 25 degree angle. After 0.5 seconds, the ball has slowed to 3 m/s. What is the change in velocity? A) 0 m/s B) 2 m/s C) 2.6 m/s D) 3 m/s E) 5 m/s Acceleration in Two Dimensions:  Acceleration in Two Dimensions 5 m/s 3 m/s A ball is rolling on a horizontal surface at 5 m/s. It then rolls up a ramp at a 25 degree angle. After 0.5 seconds, the ball has slowed to 3 m/s. What is the average acceleration? Kinematics in Two Dimensions:  Kinematics in Two Dimensions x = x0 + v0xt + 1/2 axt2 vx = v0x + axt vx2 = v0x2 + 2ax x y = y0 + v0yt + 1/2 ayt2 vy = v0y + ayt vy2 = v0y2 + 2ay y x and y motions are independent! They share a common time t Slide8:  Train ACT A flatbed railroad car is moving along a track at constant velocity. A passenger at the center of the car throws a ball straight up. Neglecting air resistance, where will the ball land? A) Forward of the center of the car B) At the center of the car C) Backward of the center of the car Demo - train Slide9:  ACT A flatbed railroad car is accelerating down a track due to gravity. The ball is shot perpendicular to the track. Where will it land? A) Forward of the center of the car B) At the center of the car C) Backward of the center of the car Projectile Motion :  Projectile Motion One marble is given an initial horizontal velocity, the other simply dropped. Which marble hits the ground first? A) dropped B) pushed C) They both hit the ground at the same time Slide11:  You are a vet trying to shoot a tranquilizer dart into a monkey hanging from a branch in a distant tree. You know that the monkey is very nervous, and will let go of the branch and start to fall as soon as your gun goes off. On the other hand, you also know that the dart will not travel in a straight line, but rather in a parabolic path like any other projectile. In order to hit the monkey with the dart, where should you point the gun before shooting? A) Right at the monkey B) Below the monkey C) Above the monkey Monkey Demo Throw ball to Monkey :  Throw ball to Monkey You throw a ball to a monkey who is on a platform 12 meters above and 5 meters to the right of you. Determine the speed and angle you should throw it such that it “just reaches” the monkey. A) Above Monkey B) At Monkey C) Below Monkey 5 m 12 m Summary of Concepts:  Summary of Concepts X and Y directions are Independent! Position, velocity and acceleration are vectors F = m a applies in both x and y direction Projective Motion ax = 0 in horizontal direction ay = g in vertical direction

04. 02. 2008
0 views

09. 01. 2008
0 views

09. 01. 2008
0 views

14. 01. 2008
0 views

17. 01. 2008
0 views

17. 01. 2008
0 views

18. 01. 2008
0 views

22. 01. 2008
0 views

04. 02. 2008
0 views

04. 02. 2008
0 views

05. 02. 2008
0 views

10. 01. 2008
0 views

25. 01. 2008
0 views

10. 01. 2008
0 views

11. 01. 2008
0 views

31. 01. 2008
0 views

07. 02. 2008
0 views

14. 02. 2008
0 views

20. 02. 2008
0 views

08. 01. 2008
0 views

05. 03. 2008
0 views

15. 01. 2008
0 views

21. 03. 2008
0 views

03. 04. 2008
0 views

28. 03. 2008
0 views

08. 04. 2008
0 views

16. 04. 2008
0 views

17. 04. 2008
0 views

23. 04. 2008
0 views

24. 04. 2008
0 views

24. 01. 2008
0 views

07. 05. 2008
0 views

02. 05. 2008
0 views

23. 01. 2008
0 views

12. 02. 2008
0 views

28. 02. 2008
0 views

22. 01. 2008
0 views

13. 01. 2008
0 views

06. 02. 2008
0 views

20. 02. 2008
0 views

09. 01. 2008
0 views

20. 01. 2008
0 views

11. 02. 2008
0 views

10. 03. 2008
0 views

11. 01. 2008
0 views