Vector and scalar quantities, Simple pendulum & Equilibrium

Scalar Quantities

Quantities with a size

Vector Quantities

Quantities with direction and size

Example of Scalar Quantities

Length, time, temperature, power, current, area, volume, speed, distance & work

Example of Vector Quantities

Force, momentum, displacement, velocity, acceleration

Parallel vectors

Vectors that act in the same line and in the same direction

How do you add parallel vectors

Arithmetically

Anti-parallel vectors

Have the same line of action but different dircetion

How to add Anti-parallel vectors

Add a convention to both side and add. eg: left = (-), right = (+)

Orthogonal Vectors

Vector are at a right angle

How do you find the vector of an orthogonal vector?

use Pythagoras theorem

How do you find the direction of an orthogonal vector?

use trigonometry

What is a simple pedulum

This a string with a bob at the end the swings freely

What is a complete Ossilation

The bob moving 360 degrees

What is the period

The time taken to complete one complete ossilation

What affects the time for a simple pendulum to take one complete oscillation

Force of the push

How long the cord is (the sorter the cord the faster it moves)

The mass of the bob

How to calculate the time for one oscillation

The average of 20 oscillations

What does it mean to be at equlibrum

A state of rest or balance due to equal action of opposing forces

Types of equlibrium

Stable

Unstable

Neutral

What is stable equilibrium

When the resultant force passes the Centre of gravity

What is unstable equilibrium

When the resultant force foes not pass through the centre of gravity

What is neutral equilibrium

If when slightly displaced, the height of it’s centre of gravity is unchanged and the body remains at rest in it’s new position