# 5.3 Oscillations Flashcards

1
Q

Displacement

A

The distance an object is from it’s rest position

2
Q

Amplitude

A

Maximum displacement

3
Q

Frequency

A

The number of oscillations per unit time at any point

4
Q

Angular Frequency and its symbol

A

(ω) The product 2pi*f

5
Q

Phase Difference and its symbol

A

(Φ) The fraction of a complete cycle between two points, expressed in radians

6
Q

Simple Harmonic Motion

A

An oscillating body where the acceleration of the body is directly proportional to its distance from a fixed point (its equilibrium position) and this acceleration is always directed to the fixed point

7
Q

SHM defining equation

A

a=-(ω^2)x

8
Q

Solutions to the equation a=-ω^2x

A

x = Acosωt, x = Asinωt

9
Q

Equation for velocity

A

v = +-ω*root(A^2-x^2)

10
Q

Maximum acceleration

A

(Sub in A for x) max a = Aω^2

11
Q

Maximum velocity

A

(Sub in A for x) max v = Aω

12
Q

Maximum displacement

A

A

13
Q

Investigation for SMH

A

Set up a mass on a spring hanging from a clamp stand. Place a position sensor beneath it. Pull down the spring and let it oscillate with its displacement being recorded. When plotted against time it should resemble a sine wave with decreasing amplitude.

14
Q

What effect does increasing the mass on a spring have on SHM time period

A

Longer time period

15
Q

What effect does the stiffness of the spring have on SHM time period

A

High stiffness = short time period

16
Q

What effect does increasing the initial displacement have on SHM time period(with a spring)

A

No effect on time period

17
Q

What effect does increasing the initial angle of a pendulum have on SHM time period

A

No effect on time period

18
Q

What effect does increasing the mass of a pendulum have on SHM time period

A

No effect on time period

19
Q

What effect does increasing the length of the string of a pendulum have on SHM time period

A

Increases time period

20
Q

How is angular frequency related to angular velocity

A

Angular frequency is the magnitude of the angular velocity

21
Q

If x = Asinωt what is velocity and acceleration

A

v = ωAcosωt a =-ω^2Asinωt (just differentiate)

22
Q

How is mechanical energy affected during SHM

A

Not affected

23
Q

How is kinetic energy affected during SHM

A

Maximum at equilibrium, minimum at highest displacement

24
Q

How is potential energy affected during SHM

A

Minimum at equilibrium, maximum at highest displacement

25
Q

Draw the graph of displacement against kinetic and potential energies

A

PE is a U

KE in ^

26
Q

Natural frequency

A

The frequency a system will oscillate at when undergoing free oscillation

27
Q

Forced Oscillation

A

A periodic driving force is applied to the system causing it to oscillate at the same frequency as the driving force

28
Q

Driving frequency

A

The frequency with which the driving force is applied to the oscillating object

29
Q

Resonance

A

Occurs when the driving frequency is equal to the natural frequency of the body being forced to oscillate. The body will oscillate at it’s natural frequency and its maximum amplitude

30
Q

Damping

A

Damping forces reduce the amplitude of an oscillation with time by removing energy from the system

31
Q

Critical damping

A

Reduces the amplitude in the shortest possible time

32
Q

Overdamping

A

The system does not oscillate but it takes longer to return to its equilibrium than with critical damping

33
Q

What does a graph of frequency against amplitude look like

A

sharp peak around natural frequency

34
Q

How does damping affect resonance

A

Reduces the maximum amplitude of resonance

35
Q

Examples of resonance (4)

A
• Organ - Swing - Glass smashing - Radio