Sunday, 22 May 2022

Term 2 Week 4 2022

Homework

Act 15A, p.173-176 Models of the Atom and Radioactivity
Ex 5A, p. 151-155 Models of the Atom
Ex 5B, p.160-171 Radioactivity

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)

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

Sunday, 13 March 2022

Term 1 Week 7 2022

Homework

Act 8B Graphs of motion p.101 (last week)
Act 8C Kinematics p.102 (last week)
Ex 4E Kinematics p.115-117 (last week)
Act 9A Vectors p.108-109 (last week)
Ex 4A Vectors p.90-94 (last week)
Act 12B Projectiles p.140-144 (last week)
Ex 4F Projectiles p.119-124 (last week)
Act 10A p.117-118 Forces (last week)
Act 10B p.123-124 Forces (last week)
Ex 4B p.97-104 Forces (last week)
Ex 4G p.125-130 Torque (last week)
Act 13A p.148-149 Circular Motion (last week)
Ex 4H p.132-134 Circular Motion (last week)
Ex 2B, p.16-18, Graphing
Ex 2C, p.19-25, Identifying Relationships and Experimental Equations
Act 14A, Energy and Springs
Act 14B, Combined Mechanics
Ex 4J, p. 143-147 Energy, Work, Power

Energy

Energy can never be created
Energy can never be destroyed
Energy can only change its form (Work is done)
Energy has the ability to make something happen, i.e. to do Work
The unit for energy is the Joule (J)
J = Kgm²s-²in fundamental units

Perpetual Motion Machine?

A Simple Proof of Conservation of Energy

Work, Energy, and Power

Work, Energy and Power Review

Gravitational Potential Energy and Kinetic Energy Skate Park PhET Link - HTML

Work

Work is a transformation (change) of energy from one form to another form. Work only occurs when something is done.

Power is the rate at which energy is transformed
Power is the rate at which work is done
Unit of power Watt (W = J/s)

Power vs Energy

Work, Energy & Power

Kinetic Energy & Gravitational Potential Energy

World's Heaviest Weight - the importance of error reduction through measurement

Sunday, 6 March 2022

Term 1 Week 5 2022

Homework

Act 8B Graphs of motion p.101 (last week)
Act 8C Kinematics p.102 (last week)
Ex 4E Kinematics p.115-117 (last week)
Act 9A Vectors p.108-109 (last week)
Ex 4A Vectors p.90-94 (last week)
Act 12B Projectiles p.140-144 (last week)
Ex 4F Projectiles p.119-124 (last week)
Act 10A p.117-118 Forces (last week)
Act 10B p.123-124 Forces (last week)
Ex 4B p.97-104 Forces (last week)
Ex 4G p.125-130 Torque
Act 13A p.148-149 Circular Motion
Ex 4H p.132-134 Circular Motion

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

Circular Motion

Velocity is always at a tangent to the circle. Even if the speed remains constant, the velocity is changing because it is accelerating.

vc = 2𝝿r/T

Centrapetal Acceleration is always toward the centre of the circle.
ac = mv2/r
Centapetal Force is the Net Force, and is also always towards the centre of the circle.