Oscillations

Question 1

displacement

Answer 1

the distance from the oscillator to the equilibrium

Question 2

amplitude

Answer 2

max displacement to the equilibrium

Question 3

time period

Answer 3

the time it takes to complete one full oscillation

Question 4

Frequency

Answer 4

the number of oscillations per unit time

Question 5

angular frequency, w

Answer 5

the rate of change of angular displacement

Question 6

what is the equation that relates angular frequency and time period

Answer 6

w = 2Pi/T

Question 7

what are the conditions fro simple harmonic motion

Answer 7

acceleration must be directly proportional to the displacement and in the opposite direction

it must act towards the equilibrium position

Question 8

two main examples of systems which undergo simple harmonic motion

Answer 8

spring and a pendulum

Question 9

when is velocity minimum

Answer 9

at the amplitude of an oscillation

Question 10

why is the velocity minimum at the amplitude of an oscillation

Answer 10

as the object changes direction

Question 11

when is velocity maximum

Answer 11

when the object passes through the equilibrium position

Question 12

how do you calculate maximum speed

Answer 12

Vmax = wA

Question 13

draw a graph for the potential energy and kinetic energy against displacement for a simple harmonic system

Question 14

what is damping

Answer 14

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

Question 15

what happens with light damping

Answer 15

> it occurs naturally
amplitude decreases exponentially
time period remains the same as A and T are independent

Question 16

what happens when heavy damping occurs

Answer 16

the amplitude decreases dramatically

Question 17

what happens during critical damping

Answer 17

object is stopped in as short time as possible without overshooting the equilibrium

Question 18

free oscillation

Answer 18

system is disturbed initially and then oscillates with no external force, it oscillates at its natural frequency

Question 19

forced oscillation

Answer 19

driving force is applied to an object which causes it to oscillate at a particular frequency

Question 20

what is resonance

Answer 20

when the driving force of the external force applied to an object is the same as the natural frequency of the object

Question 21

what happens when resonance occurs

Answer 21

> amplitude of oscillation rapidly increases and if there is no damping the amplitude will continue to increase until the system fails
as damping is increases the amplitude will decreases at all frequencies and the maximum amplitude will occur at a lower frequency

Question 22

experiment to investigate the resonance of an object

Answer 22

> suspend mass between two springs attached to oscillation generator and use a ruler parallel with the spring mass system to record the amplitude
increase the frequency of the generator slowly so that the amplitude increases, reaching maximum amplitude when the driver frequency is the same as the natural frequency
since drag due to air damps the system the amplitude should not continue to increase until the point of system failure
to increase accuracy system can be filmed and the amplitude recorded from video stills

Question 23

experiment to determine the period and frequency

Answer 23

> add a mass to the end of a spring which is attached to a stand then place a fiducial marker in line with the mass
displace the mass, to initiate simple harmonic motion
measure 10T from equilibrium position with the use of fiducial marker
take all measurements from eye level to reduce parallax error
divide by 10 to get time period
and if want frequency, frequency = 1/T
take multiple measurements and find the mean to improve accuracy

Question 24

what is the name given when the period of a simple harmonic oscillator is independent of the amplitude

Answer 24

isochronous oscillator

Question 25

how can you find the velocity at a given time

Answer 25

find the gradient

Question 26

when does maximum kinetic energy occur

Answer 26

at the equilibrium position as this is where the velocity is at its maximum

Question 27

where does maximum potential energy occur

Answer 27

at the amplitude as this is where displacement is at its maximum and total energy is conserved