Draw a free body diagram to show how a diver gains angular momentum when leaving the

Chapter 19 ● A vibration is a periodic squiggle in time ● A periodic wiggle in both space and times is a wave. A wave extends from one place to another ● Examples ○ Light, which is an electromagnetic wave that needs no medium ○ Sound, which is a mechanical wave that needs a medium ● Pendulam ○ If you suspend a stone at the end of a piece of string, we have a simple pendulum ○ The pendulum sings at a rate that ■ Depends only on the length of the pendulum ■ Does not depend on mass ● Wave Description ○ When a bob vibrates up and down, a marking pen traces out a sine curve on the paper that moves horizontally at a constant speed ○ How frequently a vibration occurs is called the frequency (Hertz or Hz) ○ 1 Hz is a vibration that occurs once each second ○ Mechanical objects (eg pendulums) have frequencies of a few Hz ○ Sound has a frequency of a few 100 or 1000 Hz ○ Radio waves have frequencies of a few million Hz ○ Cell phones operate at a few billion Hz (GHz) ● Period and Frequency ○ T = 1/f ○ F = 1/T ● Wave motion ○ Waves transport energy not matter ○ Examples ■ Ripples in water carry no water across the pond ■ Waves travel across grass on a windy day ■ Molecules in air propagate a disturbance through air ○ Wave speed ■ Describe how fast a disturbance m