PHY 2048C General Physics I with lab Spring 2011 CRNs 11154, 11161 & 11165

PHY 2048CGeneral Physics I with lab

Spring 2011CRNs 11154, 11161 & 11165

Dr. Derrick BoucherAssoc. Prof. of Physics

Session 3-4, Chapter 4

Chapter 4

• Simple Projectile Motion

•Circular motion

•Centripetal Acceleration in Uniform

Circular Motion

•Rotational/Translational comparisons

Chapter 4 Practice Problems

Chap 4: 7, 37, 47, 49, 61, 65

Unless otherwise indicated, all practice material is from the “Exercises and Problems” section at the end of the chapter. (Not “Questions.”)

2-D Kinematics

•The x and y components of the motion are treated

separately.

•Do not mix up x and y data when setting up and

solving equations.

•Good strategy: separate paper into “X” and “Y”

columns.

•Certain events can connect x and y motion at

particular moments (certain t values).

2-D Kinematics EquationsGeneral 2-D motion

“Projectile” motionay = -g, ax = 0

Example problem Chapter 4 #10 (p. 120)

Circular Motion•Radius is constant (or unimportant)•“Position” is an angle, in radians, θ•Velocity is radians per second, ω (that’s “omega”, not “curly double-u.”)•Acceleration can be along the tangent to the circle, at , or in a radial or “centripetal” direction, ac .

2rad/sin with rat

s

θ

Example problem Chapter 4 #38 (p. 122)

Centripetal Acceleration

Example problem Chapter 4 #62 (p. 123)