90 likes | 227 Views
Vibrations and Waves. Chapter 14 Supplement. Our perceptions of waves. Imagine a pendulum. As the bob is displaced from the equilibrium point (the center), there is a force that attempts to RESTORE its equilibrium.
E N D
Vibrations and Waves Chapter 14 Supplement
Imagine a pendulum • As the bob is displaced from the equilibrium point (the center), there is a force that attempts to RESTORE its equilibrium. • It’s motion repeats in a regular cycle, wherein the trips back and forth take the same amount of time. • This is called periodic motion.
Simple Harmonic Motion Motion that results when the force that restores an object to its equilibrium is directly proportional to the displacement of that object. Mathematically speaking:
Describing SHM • Period – “T” – the time needed for an object to repeat one complete cycle of motion. • Inverse of period = frequency, which is measured in Hertz (Hz) • Amplitude – “A” – the maximum distance that an object moves from equilibrium.
Consider a spring… • When there is no mass on the spring, is the spring stretched to any extent? • When we do attach a mass to the spring, what factors are going to affect the extent to which the spring is stretched? • Does the spring itself affect the extent to which it is stretched?
The Mass on the Spring We can also talk about the potential energy associated with