Thursday, 24 July 2025

Week 2 Term 3 2025 Internal Resistance of a Battery & Kirchhoff's Laws

Homework

Act 13A, p.205-206 Level 2 D.C. Circuit Revision

Act 13B, p.210-211 Internal Resistance of a Battery

Ex 6A, p.251-253 Resistor Networks

Ex 6B, P.261-262 Internal Resistance of a Battery

Electrical Charge

Current

Current is the rate of flow of Charge

I = Δq/Δt

Current

Voltage

Voltage (Potential Difference) is the change in energy (work done) to each coulomb of charge between two points on a circuit, or two points across an electric field

Voltage

Voltage (Potential Difference) is the change in energy (work done) to each coulomb of charge between two points on a circuit, or two points across an electric field

V = ΔE/Q

Ohm's Law & Resistance

Power

Circuit Symbols

Ohm's Law

Ohm's Law - PhET App

D.C. Circuit Construction Kit - PhET App

Ohm's Law

Internal Resistance of a Battery

Batteries can be thought of as having an ideal voltage supply E.M.F. (Electromotive Force) in series with an internal resistance

V = 𝛆 - Ir

How to find the internal resistance of a battery

Kichhoff's Laws

Kirchhoff’s Current Law
“At any junction in a circuit, the total current entering the junction equals the total current leaving the junction”
Kirchhoff’s Voltage Law
“Around any closed path of a circuit, the total of all the potential differences, V, is zero”

Kirchhoff's Rules for Circuit Analysis - Explanation

Kirchhoff's Rules for Circuit Analysis - Example 1

Kirchhoff's Rules for Circuit Analysis - Example 2

Kirchhoff's Rules for Circuit Analysis - Example 3

Tuesday, 24 June 2025

Week 9 Term 2 2025 Simple Harmonic Motion (S.H.M.)

Homework:

2D Momentum and Centre of Mass C.O.M.

Ex 4A, p.100-102, C.O.M.
Ex 4B, p.108-112, Momentum & C.O.M. in 1D
Ex 4C, p.116-122, Momentum & C.O.M. in 2D
Act 7A, p.87-88 Motion, Force and Energy
Act 7B, p.91-92 Impulse
Act 7C, p.95-96 Conservation of Momentum
Act 7D, p.100-101 C.O.M.

Circular Motion

Act 8A, p.120-121 Horizontal Circles and Banked Corners
Act 8B, p.124-125 Vertical Circles
Act 8C, p.129 Sattelites
Ex 4D, p.128-131, Banked Corners (Circular Motion)
Ex 4E, p.138-142, Vertical Circles
Ex 4F, p.145-147, Gravity
Ex 4G, p.153-156 Satallites

Rotational Motion

Act 9A, p. 139-140, Angular Motion
Act 9B, p. 144-145, Torque - Rotational Inertia
Act 9C, p.149-150, Angular Momentum
Act 9D, p.153-154 Rotational Kinetic Energy
Ex 4H, p.160-162, Rotational Kinematics
Ex 4H, p.160-162, Rotational Kinematics
Ex 4I, P.167-171, Rotational Force & Momentum
Ex 4J, p.175-177, Rotational Kinetic Energy

Simple Harmonic Motion

Act 10A, p. 148, Simple Harmonic Motion (SHM)
Act 10B, p.153, Reference CIrcle
Act 10C, p. 158-160, SHM - displacement, velocity, acceleration
Act 10D, p. 164-165, Springs and Pendulums
Act 10E, p. 172, SHM Energy, Damped, Driven, Resonance
Ex 4K, p.184-187, Pendulums and Bouncing Springs
Ex 4L, p.191-194, SHM

Simple Harmonic Motion - SHM

Masses & Springs PhET Lab

Simple Pendulum PhET Lab

SHM

Simple Harmonic Motion: Crash Course Physics

Pendulum Wave Demonstration

SHM & Energy

Energy of Simple Harmonic Oscillators

Damped SHM

Damping of Simple Harmonic Motion

Damped SHM & Resonance

PhET - Resonance Lab

Tacoma Bridge Collapse

How The Millennium Bridge Became The World's Most Wobbly Bridge

Tuesday, 10 June 2025

Week 7 Term 2 2025 Rotaional Motion

Homework:

C.O.M. & 2D momentum

Ex 4A, p.100-102, C.O.M.
Ex 4B, p.108-112, Momentum & C.O.M. in 1D
Ex 4C, p.116-122, Momentum & C.O.M. in 2D
Act 7A, p.87-88 Motion, Force and Energy
Act 7B, p.91-92 Impulse
Act 7C, p.95-96 Conservation of Momentum
Act 7D, p.100-101 C.O.M.

Circular Motion

Act 8A, p.120-121 Horizontal Circles and Banked Corners
Act 8B, p.124-125 Vertical Circles
Act 8C, p.129 Sattelites
Ex 4D, p.128-131, Banked Corners (Circular Motion)
Ex 4E, p.138-142, Vertical Circles
Ex 4F, p.145-147, Gravity
Ex 4G, p.153-156 Satallites

Rotational Motion

Act 9A, p. 139-140, Angular Motion
Act 9B, p. 144-145, Torque - Rotational Inertia
Act 9C, p.149-150, Angular Momentum
Act 9D, p.153-154 Rotational Kinetic Energy
Ex 4H, p.160-162, Rotational Kinematics
Ex 4I, P.167-171, Rotational Force & Momentum
Ex 4J, p.175-177, Rotational Kinetic Energy

Rotational Inertia

Torque

Angular Momentum

Angular Momentum - Sixty Symbols

Gyroscopic Precession

Slow Motion Flipping Cat Physics

Counter Steering Physics

The Bizarre Behavior of Rotating Bodies, Explained

Ellipzoids and the Bizarre Behavior of Rotating Bodies

Thursday, 29 May 2025

Week 5 Term 2 2025 Rotational Kinematics

Homework:

C.O.M. & 2D momentum

Ex 4A, p.100-102, C.O.M.
Ex 4B, p.108-112, Momentum & C.O.M. in 1D
Ex 4C, p.116-122, Momentum & C.O.M. in 2D
Act 7A, p.87-88 Motion, Force and Energy
Act 7B, p.91-92 Impulse
Act 7C, p.95-96 Conservation of Momentum
Act 7D, p.100-101 C.O.M.

Circular Motion

Act 8A, p.120-121 Horizontal Circles and Banked Corners
Act 8B, p.124-125 Vertical Circles
Act 8C, p.129 Sattelites
Ex 4D, p.128-131, Banked Corners (Circular Motion)
Ex 4E, p.138-142, Vertical Circles
Ex 4F, p.145-147, Gravity
Ex 4G, p.153-156 Satallites

Rotational Motion

Act 9A, p. 128-129, Angular Motion
Ex 4H, p.160-162, Rotational Kinematics

Radians

Radian Measure is used so that we can easily calculate an arc length, d (m), given an angle, 𝛉 (Rad) and the radius, r (m).

d = r𝛉

This in turn allows us to relate velocity, v (ms-1) to angular velocity ⍵ (rads-1), in the same way. Note that Angular Velocity may also be called Angular Frequency.