ch. 4 projectile motion - siena science · copyright © 2008 pearson education, inc., publishing as...

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.

Ch. 4 Projectile Motion

•  Finding the acceleration vector

•  Motion in 2 dimensions

•  Motion map

•  Equations of motion: x, y

•  Monkey hunting - starring George Hassel

•  Projectile Motion Worksheets


Acceleration The average acceleration of a moving object is defined as the vector

As an object moves, its velocity vector can change in two possible ways. 1. The magnitude of the velocity can change, indicating a change in speed, or 2. The direction of the velocity can change, indicating that the object has changed direction.


Tactics: Finding the acceleration vector


EXAMPLE 4.1 Through the valley


General Principles


A particle undergoes acceleration while moving from point 1 to point 2. Which of the choices shows the velocity vector as the object moves away from point 2?

QuickCheck 4.1

Slide 4-23


A particle undergoes acceleration while moving from point 1 to point 2. Which of the choices shows the velocity vector as the object moves away from point 2?

QuickCheck 4.1

Slide 4-24


Projectile Motion


Projectile Motion

Projectile motion is made up of two independent motions: uniform motion at constant velocity in the horizontal direction and free-fall motion in the vertical direction. The kinematic equations that describe these two motions are


Projectile Motion


EXAMPLE 4.4 Don’t try this at home!

QUESTION:


EXAMPLE 4.4 Don’t try this at home!


A heavy red ball is released from rest 2.0 m above a flat, horizontal surface. At exactly the same instant, a yellow ball with the same mass is fired horizontally at 3.0 m/s. Which ball hits the ground first?

A.  The red ball hits first.

B.  The yellow ball hits first.

C.  They hit at the same time.

QuickCheck 4.5

Slide 4-53

Think-Pair-Share


A heavy red ball is released from rest 2.0 m above a flat, horizontal surface. At exactly the same instant, a yellow ball with the same mass is fired horizontally at 3.0 m/s. Which ball hits the ground first?

A.  The red ball hits first.

B.  The yellow ball hits first.

C.  They hit at the same time.

QuickCheck 4.5

Slide 4-54

Think-Pair-Share


A 100 g ball rolls off a table and lands 2.0 m from the base of the table. A 200 g ball rolls off the same table with the same speed. It lands at distance

A.  1.0 m. B.  Between 1 m and 2 m. C.  2.0 m. D.  Between 2 m and 4 m. E.  4.0 m.

QuickCheck 4.6

Slide 4-55

Think-Pair-Share


A 100 g ball rolls off a table and lands 2.0 m from the base of the table. A 200 g ball rolls off the same table with the same speed. It lands at distance

A.  1.0 m. B.  Between 1 m and 2 m. C.  2.0 m. D.  Between 2 m and 4 m. E.  4.0 m.

QuickCheck 4.6

Slide 4-56

Think-Pair-Share


Problem-Solving Strategy: Projectile Motion Problems


Projectile Motion Worksheets

•  Do Worksheet 1 & 2 •  Group whiteboard and share 1-2 hard ones at

the end •  Finish the rest at home; bring on Tuesday!


Upcoming Assignments

•  MasteringPhysics online HW due tonight, Thursday 9/20 by 11 pm

•  Read Chapter 4 to the end by Tuesday 9/25 •  Pre-class MasteringPhysics assignment due before

class on Tuesday 9/25 •  MasteringPhysics online HW due, Thursday 9/27 by

11 pm

•  Exam 1 coming up on 10/2

ch. 4 projectile motion - siena science · copyright © 2008 pearson education, inc., publishing as...

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