vce physics units 3&4 exam revision lecture vce physics units 3&4 presented by: alevine magila exam

Download VCE Physics Units 3&4 Exam Revision Lecture VCE Physics Units 3&4 Presented by: ALEVINE MAGILA Exam

Post on 01-Mar-2020

0 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • VCE Physics Units 3&4

    Presented by: ALEVINE MAGILA

    Exam Revision

    Lecture

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • So then what can I provide in this lecture?

    • Detailed look at VCAA Exam structures and styles

    • Help you to identify any weaknesses you have

    • Explain hard ‘separator’ questions from VCAA

    • Strategies to tackle hard questions

    • General advice from a past student

    If what you’re looking for is content and revision summaries, have a look at

    the course notes or topic tests.

    Today’s Lecture

    4

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • Magnetic Field Vectors

    6

    2011 Physics Exam 2

  • Magnetic Field Vectors

    7

    2011 Physics Exam 2

  • Magnetic Field Vectors

    8

    2013 Physics Exam

  • Satellite Motion

    9

    2013 Physics Exam

  • Astronauts in orbit only have one force acting on them: the weight force.

    Therefore,

    Σ𝐹 = 𝐹𝑔

    Σ𝐹 = 𝐺𝑀𝑚

    𝑅2 = 𝐹𝑔

    SATELLITE MOTION

    10

    In year 12, we model satellite motion as uniform circular motion. We can account

    for this in our equations:

    Σ𝐹 = 𝑚𝑣2

    𝑅 = 𝐺𝑀𝑚

    𝑅2 = 𝐹𝑔

    Σ𝐹 = 𝑚𝑣2

    𝑅 = 4𝜋2𝑅

    𝑇2 = 𝐺𝑀𝑚

    𝑅2 = 𝐹𝑔

    𝑎 = 𝑣2

    𝑅 = 4𝜋2𝑅

    𝑇2 = 𝐺𝑀

    𝑅2 = 𝑔

  • Satellite Motion

    11

    2013 Physics Exam

  • DC Motors

    12

    2014 Physics Exam

  • DC MOTORS

    13

  • DC Motors

    14

    2014 Physics Exam

  • DC Motors

    15

    2014 Physics Exam

  • Explanation Questions

    16

    The best advice I’ve heard when it

    comes to explanation-style

    questions?

    Be specific, and answer the question.

  • DC Motors

    17

    2014 Physics Exam

    • Magnetic forces act on the coil create a torque.

    • This torque causes the magnetic field to rotate

  • DC Motors

    18

    2016 Physics Exam

    • The magnetic forces acting on the coil are at a

    maximum when the coil is at a flat, horizontal

    position

    • Therefore, a horizontal position if the best position

    for the motor to start from rest

  • Charged Particles Moving Through a

    Magnetic Field

    19

    A moving charge in a magnetic field will experience a magnetic force. This

    force can be calculated from the equation

    𝐹 = 𝑞𝑣𝐵 From Newton’s second law, we know that whenever there is a net force, there

    is an acceleration. Since there is a net magnetic force on a moving charge

    through the magnetic field, it must be accelerating.

    In reality, a moving charge does not change speed through a magnetic field –

    it changes direction. Therefore, charged particles experience a centripetal

    acceleration when they move through a magnetic field.

    This yields the equation

    𝑚𝑣2

    𝑅 = 𝑞𝑣𝐵

    The direction of the magnetic force on a charged particle can be calculated

    using the right-hand slap rule, except this time, the thumb points in the

    direction of the charge’s velocity instead of in the direction of the current.

    If the charge is negative, the thumb points in the opposite direction to the

    charge’s velocity.

  • Particle Accelerators

    20

  • Weight Force/ Normal Force In

    Satellites

    21

    2016 Physics Exam

    • It is possible to experience weightlessness without being truly

    weightless

    • This occurs when the normal force acting on someone is 0 i.e

    they are in freefall

    • This gives them the sensation of being weightless, known as

    apparent weightlessness

    • Thus Emily is incorrect – it IS possible to FEEL weightless without

    needing to be in deep space

  • Graph of Gravitational Force vs

    Distance

    22

    2002 Physics Exam

    • There are approximately

    13 squares

    • Each square has a value

    of 1000 x 3 x 106 = 3 x

    109 J

    • Therefore, the total energy

    required equals 13 x 3 x

    109 J

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • Faraday’s Law

    24

    2015 Physics Exam

  • Induced EMF

    25

    2011 Physics Exam 2

  • Transformers

    26

    2014 Physics Exam

  • Making calculations about an electrical generator (such as calculating the

    average power it produces) can be tricky because induced EMF is always

    varying.

    To compensate for this, physicists sometimes like to use a quantity called

    the root mean square or RMS voltage.

    This is the DC voltage it would take to produce the same average power as

    an oscillating AC voltage.

    To find the RMS voltage, we use the formula

    𝑉𝑅𝑀𝑆 = 𝑉𝑝

    2

    𝑉𝑝𝑒𝑎𝑘 is the ‘peak’ voltage or the maximum voltage induced (this can be

    read from a graph or an oscilloscope).

    PEAK VOLTAGE AND RMS VOLTAGE

    27

  • Transmission of Electricity

    28

  • Transmission of Electricity

    29

    • Transformers significantly increases voltages to very high levels

    • For a constant power, the voltage and the current are inversely

    proportional (P = IV)

    • An increase in voltage causes a decrease in current

    • Decreasing the current decreases the power loss (𝑃𝑙𝑜𝑠𝑠 = 𝐼 2𝑅),

    thereby reducing transmission losses

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • Pulley Questions

    31

  • Pulley Questions

    32

  • Banked Tracks

    33

  • When working through banked track problems, here are some

    useful tips when through these types of questions:

    • Draw a diagram (if one isn’t already supplied to you)

    • Draw a force triangle. Again, the only forces acting on the

    car that is moving at the design speed should be the weight

    force and the normal force

    • Note that for many questions, you won’t actually need the

    mass of the car to find the answer

    Tackling Banked Track Problems

    34

  • Vertical Circular Motion

    35

  • Length Contraction

    39

  • Muons

    40

  • Muons

    41

    • Why did the experiments

    observe more muons

    than expected?

    • Because the half-life of

    the muons, relative to the

    experimenters, increased.

    • This led to a higher

    number of muons

    reaching the detector

    without decaying

  • • Introduction

    • How do things move without contact?

    • How are fields used to move

    electrical energy?

    • How fast can things go?

    • How can waves explain the behavior

    of light?

    • How are light and matter similar?

    • Final tips and tricks

  • The Doppler Effect

    43

    Emily is waiting to cross the road when an ambulance swerves around the corner with its sirens blaring. When the ambulance rushes towards Emily, the pitch of the siren seems to increase. As the ambulance passes Emily and drives into the distance, the pitch of the siren seems to decrease. Explain this effect.

    • The change in pitch of the siren

Recommended

View more >