# Category: Physics A2

## Parallax, Standard Candles and Measuring Astronomical Distances

A standard candle is an astronomical object of which the intrinsic brightness and distance from the Earth are known. By comparing the apparent brightness of a star with the apparent brightness of the standard candle, it is possible to work out the distance of the star from Earth. To do …

## Non-Relativistic Doppler Effect – All You Need To Know

The concept around the Doppler effect is basically how much a wave stretches or bunches due to the speed it is travelling at. The most common scenario you will experience the Doppler effect will be with an Ambulance. As you here the sirens approach you, the waves will have been ‘squished’ or compressed producing …

## Gravitational Potential – Non-Uniform and Uniform Fields

The gravitational potential energy of an object is the potential energy per kilogram of an object placed at that specific point.  For a Uniform Field The equation below applies to when there is a uniform field such as when we are talking about being very close to the …

## All You Need To Know About Momentum

In theory, every moving and colliding objects works through momentum. The momentum of an object can be calculated with the following equation: p = mv  Where m = mass (kg) and v = velocity (m/s). To understand more about momentum, consider two imaginary spacecraft colliding and joining together. …

## Calculating the Radius of a Geostationary Orbit

To calculate the radius of a geostationary orbit, the centripetal force must equal the gravitational force on the satellite or mass.. Through the use of re-arranging the above equation, we can come to the equation: r³ = G (m2) T² / 4π² We  know that (m2) is the mass of the earth …

## Circular Motion and Centripetal Force

Circular motion is caused by an unbalanced force acting towards the center of the circle. This force is called the centripetal  force which needs to be provided by a physical mechanism. e.g. gravity, friction, tension etc. In a time △t, mass (m) moves from position (1) to position (2). The length of …

## Features Of A Simple Harmonic Motion

For a simple harmonic motion (SHM) to occur, the following elements need be present: The SHM is always stationary at the maximums and minimums. For example, a when a pendulum is swinging at it’s highest, it will always be stationary at that moment. The displacement after an infinite …

## Resonance In Simple Harmonic Motions

For resonance to occur, the driving frequency (frequency you push it at) has to equal the natural frequency with the natural frequency being the frequency something vibrates if you just pulled it and let it go.For a pendulum, T = 2π√(L/G) with f = 1/T. Therefore, f = 1/2π x √(G/L). …