Physics 5.3 Oscilations

Question 1

What is the displacement, amplitude, frequency and period?

Answer 1

-Displacement: the distance an object moves from its equilibrium position, may be positive or negative
-Amplitude: maximum displacement and will always be positive
-Frequency: number of oscillations per unit time at any point (Hz)
-Period: is the time taken for one complete pattern of oscillation at any point

Question 2

What is Angular frequency and its equations?

Answer 2

-The rate of change of phase
-ω=2π/T
-ω=2πf

Question 3

What is phase difference?

Answer 3

-Φ is the fraction of a complete cycle between two oscillating points, measured in degrees and radians

Question 4

Describe a body that is performing simple harmonic motion?

Answer 4

-A body that oscillates with its acceleration directed towards a fixed point that is directly proportional to the negative of the displacement

Question 5

Answer 5

Use X=AcosWt when the object is released from maximum displacement and x=Asinwt would be used when the object displacement is 0 at t=0

Question 6

What is the equations for velocity of a body undergoing S.H.M and when does maximum acceleration and velocity occur and equations for them?

Answer 6

Question 7

Draw a graph for energy changes in a pendulumn and mass on a spring performing S.H.M as their displacement changes?

Answer 7

-Switch pendelumn and mass on a spring with graphs (written wrong on card)

Question 8

Draw the acceleration-displacement graph and velocity-displacement graph for an object performing s.h.m?

Answer 8

Question 9

Describe the velocity,acceleration and displacement at these points on the graph?

Answer 9

Question 10

Draw the acceleration and velocity-time graphs for this displacement time graph?

Answer 10

Question 11

Define Damping forces and what is natural damping?

Answer 11

-Damping forces: Forces that reduce the amplitude of an oscillation with time, due to energy being removed from the oscillating system
-Natural Damping: Damping that occurs due to the effect of air resistance or frictional forces

Question 12

What are the uses of artificial damping?

Answer 12

-It ensures the amplitude of the vibrations die down quickly so as to not lead to discomfort for example in a cars suspension

Question 13

What is the difference between heavy damping(examples) and light damping?

Answer 13

-In light damping, small damping forces exist and oscillation and period gradually decreases.
-In heavy damping, no to little oscillation occurs and the body moves back to its equilibrium position, for e.g. suspension of a car

Question 14

What is free oscillations, natural frequency and Forced oscillations?

Answer 14

-Free oscillations: no external forces so system oscillates at its natural frequency
-Natural Frequency: frequency at which a system undergoing free oscillation
-Forced oscillations: when an external force is applied to keep the body oscillating

Question 15

What is driving frequency and resonance?

Answer 15

-Driving frequency: frequency of the driving force applied to an oscillating object
-Resonance: in forced oscillations when the driving frequency is equal to the natural frequency of the system being forced to oscillate, this results in the object oscillating at its natural frequency/ maximum amplitude

Question 16

What are the effects of damping on the amplitude of resonant oscillation?

Answer 16

-Reduces the amplitude of the driven oscillation and slightly reduces the frequency

Question 17

What are the uses of resonance?

Answer 17

-Allow you to generate vibrations of a specific frequency (for e.g. musical instruments).