Term 2 Week 6 2021

  Homework:

• Act 15A, p. 173-176, Particles and Half-Life
• Act 16A, p. 181, Nuclear Reactions
• Act 5A, p,53, Pulses and Waves
• Worksheet on Superposition and Reflection

Basic Properties of Waves

waves transfer energy through a medium without transferring the medium itself

• Cycle - a basic repeating unit in a wave
• Amplitude A (m) - the distance from the middle point to the top of a crest, or bottom of a trough
• Wavelength 𝜆 (m) - the distance/length of one cycle
• Period T (s = s per cycle) - the time it takes for one cycle to pass a point
• Frequency f (Hz = cycles per second) - the number of cycles that pass in one second

T = 1/f & f = 1/T

• Wave Speed v (ms-1) the speed of a wave

v = 𝜆/T & v = f𝜆

Wave Properties

Frequency & Period

Wave Phase

Pendulum Waves

Longitudinal Waves

particle displacement in the medium is parallel to the direction of wave propagation e.g. sound waves, primary earthquake waves

Transverse Waves

particle displacement in the medium is perpendicular to the direction of wave propagation e.g. light and other electromagnetic waves, secondary earthquake waves

• Superposition of Waves: two waves traveling through each other will not change each other motion in any way, but they will add to one another when they overlap
• Constructive Interference - Reinforcement - In Phase
• Destructive Interference - Cancellation - Out of Phase

PhET Waves on a String App - link

Reflection on A String

Hard Boundary

Wave reflects on opposite side (opposite phase)

Same Amplitude, A

Same Wavelength, 𝛌

Same Wave Speed, v

Reflection on A String

Soft Boundary

Wave reflects on same side (same phase)

Same Amplitude, A

Same Wavelength, 𝛌

Same Wave Speed, v

Refraction on A String

Fast to Slow Boundary

Relation of waves to Incident Wave

Reflected Wave - same speed - same wavelength 𝛌 - opposite phase

Refracted Wave - slower speed - smaller wavelength 𝛌 - same phase

Refraction on A String

Slow to Fast Boundary

Relation of waves to Incident Wave

Reflected Wave - same speed - same wavelength 𝛌 - same phase

Refracted Wave - faster speed - larger wavelength 𝛌 - same phase

Term 2 Week 4 2021

  Homework:

• Act 15A, p. 173-176, Particles and Half-Life
• Act 16A, p. 181, Nuclear Reactions

Nuclear Reactions:

• Conservation of Atomic Number
• Conservation of Nucleon Number
• Conservation of Mass-Energy E = Δmc2

E = Δmc2

Nuclear Fusion in the Sun

Binding Energy comes from the change in mass from individual nucleons to being combined into a nucleus. This is energy lost by the nucleons joined together in a nucleus and must be returned in order to separate the nucleons

E = Δmc2

Element formation in Stars Nuclear Fusion

Binding Energy Per Nucleon

Mass Per Nucleon

Nuclear Reactions

Fission Fusion and Radioactive Decay

Fission & Fusion

Natural Nuclear Fission Reactor

Term 2 Week 3 2021

 Homework:

• Act 11A, p.130, Momentum and Impulse
• Act 11B, p. 133-134, Collisions
• Act 10A, p. 117-118, F = ma
• Act 10B, p. 123-124, Force, Motion, Equilibrium, Torque
• Act 15A, p. 173-176, Particles and Half-Life

Study Pass Models of the Atom

Models of the Atom

History of the Atom

Models of the Atom Timeline

Discovery of the Electron: Cathode Ray Tube Experiment

Discovery of the Nucleus: Rutherford's Gold Foil Experiment

Charge of an Electron: Millikan's Oil Drop Experiment

Atomic Structure: Discovery of the Neutron

Parts of the Atom

Isotopes

Isotopes are versions of an atom or an element that have the same number of protons, but different numbers of neutrons

What are Isotopes?

Radioactive Decay

Alpha, Beta & Gamma Radiation

• Alpha particles are emitted by a larger nucleus that has too many Protons
• Beta particles are emitted by a nucleus that has too many Neutrons
• Gamma photons are emitted by a nucleus that has too much Energy (is in an exited state)

• PhET Alpha Decay app can be found here
• PhET Beta Decay app can be found here

Alpha Decay

Beta Decay

Radiation

Types of Radiation

Is radiation dangerous?

The Most Radioactive Places on Earth

Millisieverts and Radiation - Sixty Symbols

Half Life Calculations

Term 2 Week 1 2021

 Homework:

• Act 11A, p.130, Momentum and Impulse
• Act 11B, p. 133-134, Collisions
• Act 10A, p. 117-118, F = ma
• Act 10B, p. 123-124, Force, Motion, Equilibrium, Torque

Forces

Mass on a Slope

Drawing a Free Body Diagram

Net Force - PhET Application - link here

What is a Force?

What Forces are Acting on You?

Best Film on Newton's Third Law Ever

What is Gravity

The Difference Between Mass & Weight

Misconception About Falling Objects

Torque

𝝉 = F L⦜
𝝉: Torque (Nm)
F: applied Force (N)
L⦜: Length of lever at right angles to the applied force (m)


• Torque (Moments) in Level 2 Physics will involve Static Systems
• Therefore the Torques are balanced and the Forces are balanced - Newton's Laws of Motion apply to turning forces as well as linear forces
• PhET - Torque Balancing Act simulation
Bridge support forces moments


Torque (Moments anout a point)
Static (unmoving) systems will be used for this section. Therefore all forces, linear and turning, are balanced








Torque

Term 1 Week 11 2021

 Homework:

• Act 11A, p.130, Momentum and Impulse
• Act 11B, p. 133-134, Collisions

Momentum

Conservation of Momentum

In the absence of external forces the total momentum of a system is always conserved

Impulse

The change in Momentum for a single object

ΔP = Pf - Pi

&

ΔP = FΔt

&

ΔP = mΔv

• The unis are eithor Ns or kgms-1 , this is the same unit and the one that is used depends on the context
• Impulse on one object is always equal and opposite to the impulse on the other onject - Newton's Third Law

Physics of Car Crashes (Impulse)

Impulse

Impulse

Impulse examples///Homemade Science with Bruce Yeany

Momentum

Impulse