Chapter 17 - Oscillations

Question 1

Displacement

Answer 1

the distance of a particle from its equilibrium position

Question 2

Amplitude

Answer 2

Maximum displacement from the equilibrium position

Question 3

Period

Answer 3

the time taken for one complete oscillation

Question 4

Frequency

Answer 4

the number of oscillations per unit time

Question 5

Phase difference

Answer 5

the fraction of an oscillation between the position of two oscillating objects

Question 6

angular frequency

Answer 6

rate of change of angular position

Question 7

Outline SHM

Answer 7

A type of oscillation where the acceleration of the particle is directly proportional to the displacement from the equilibrium position, and acts towards the equilibrium position.

Question 8

main SHM equation

Answer 8

a = -ω^2x
a is acceleration
x is the displacement
ω is the angular frequency

Question 9

Why is the minus sign used in the main shm equation

Answer 9

to show acceleration is always in the opposite direction to displacement

Question 10

SHM exhibits isochronous oscillation, what does this mean?

Answer 10

period of oscillation is independent of amplitude

Question 11

Equation for displacement of SHM oscillation starting at equilibrium position

Answer 11

x = Asinωt

Question 12

Equation for displacement of SHM oscillation starting at amplitude position

Answer 12

x = Acosωt

Question 13

Outline behavior of velocity and acceleration during SHM

Answer 13

• Acceleration max at amplitude points where displacement is max
• Velocity is max when amplitude is zero and displacement is 0 at equilibrium position

Question 14

Equation for velocity in SHM

Answer 14

v = ±√(A^2-x^2 )

Question 15

Equation for vmax of shm

Answer 15

vmax = ωA

Question 16

Describe the energy transfers in SHM

Answer 16

• KE is max at equilibrium points where amplitude = 0

- PE is max at amplitude points where KE=0

Question 17

Define damping

Answer 17

process by which the amplitude of the oscillations decreases over time. This is due to energy loss to restrictive forces such as drag or friction

Question 18

outline light damping

Answer 18

light damping occurs naturally e.g. a pendulum oscillating in air, and the amplitude decreases exponentially.

Question 19

outline heavy damping

Answer 19

amplitude decreases dramatically e.g. pendulum in water

Question 20

outline critical damping

Answer 20

objects stops before one oscillation, e.g. pendulum in treacle

Question 21

Outline free oscillations

Answer 21

when the object oscillates without any external forces being applied, it oscillates at it’s natural frequency, this is free oscillation

Question 22

outline forced oscillations

Answer 22

when there is a periodic driving force applied to an object, which causes it to oscillate at a particular frequency

Question 23

Outline resonance

Answer 23

when the driving force applied to an object is the same as the natural frequency of the object, resonance occurs. This is when the amplitude of oscillation rapidly increases, and if there is no damping, the amplitude will continue to increase until the system fails.

Question 24

When does maximum amplitude occur regarding resonance

Answer 24

lowest frequency