Term 2 Week 5 2018

Homework:

• Ex 4G, p. 125-130, Torque, Static Moments
• Ex 5A, p.151-155, Models of the Atom
• Ex 5B, p. 160-171, Half-Life

Alpha, Beta, Gamma Ionising Radiation

• Ionising Radiation is radiation that will give a charge to matter. This includes EM radiation (photons) that have enough energy to ionise - e.g. X-Rays and 𝜸 - Rays. This also includes charged particles such as α and 𝞫 particles.

Ionising Radiation

Types of Radiation Alpha, Beta, Gamma

Radiation vs Radioactive Atoms

Is Radiation Dangerous?

Radioactivity: Expect the unexpected

EM Spectrum

Term 2 Week 5 2018

Homework:

• Ex 4G, p. 125-130, Torque, Static Moments
• Ex 5A, p.151-155, Models of the Atom

Models 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

Term 2 Week 3 2018

Homework:

• Ex 4J, p. 143-147 Energy, Work, Power
• Ex 4I, p.137-141, Springs
• Ex 4G, p. 125-130, Torque, Static Moments

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

Term 2 Week 2 2018

Homework:

• Ex 4J, p. 143-147 Energy, Work, Power
• Ex 4I, p.137-141, Springs

PhET - Hooke's Law & Springs - HTML

Intro to Springs and Hooke's Law

Potential Energy Stored in a Spring

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

Term 2 Week 1 2018

Homework

• 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-²  in fundamental units

Perpetual Motion Machine?

A Simple Proof of Conservation of Energy

Work, Energy, and Power

Work, Energy and Power Review