View source for Newton's Law of Universal Gravitation

==Key Stage 3==
===Meaning===
'''Newton's Universe Theory of Gravitation''' is a [[Scientific Theory|scientific theory]] developed by Sir [[Isaac Newton]] that [[explain]]s that the [[planet]]s are held in [[orbit]] around [[The Sun]] by [[gravity]].

===About Newton's Universal Theory of Gravitation===
: Before [[Isaac Newton|Newton]] [[scientist]]s had many different ideas about how [[planet]]s were held in [[orbit]] around [[The Sun]]. Some thought they were held by [[magnetism]] and others thought the [[planet]]s were held in invisible crystal [[sphere]]s around [[The Sun]].
: [[Isaac Newton|Newton]] was the first to realise that the [[force]] which pulls [[object]]s to the ground on [[Earth]] might be the same as the [[force]] that keeps [[planet]]s [[orbit]]ing [[The Sun]] and [[The Moon]] [[orbit]]ing the [[Earth]].

==Key Stage 4==
===Meaning===
'''Newton's Universe Theory of Gravitation''' is a [[Scientific Theory|scientific theory]] developed by Sir [[Isaac Newton]] that [[explain]]s that the [[planet]]s are held in [[orbit]] around [[The Sun]] by [[gravity]].

===About Newton's Universal Theory of Gravitation===
: Before [[Isaac Newton|Newton]] [[scientist]]s had many different ideas about how [[planet]]s were held in [[orbit]] around [[The Sun]]. Some thought they were held by [[magnetism]] and others thought the [[planet]]s were held in invisible crystal [[sphere]]s around [[The Sun]].
: [[Isaac Newton|Newton]] was the first to realise that the [[force]] which pulls [[object]]s to the ground on [[Earth]] might be the same as the [[force]] that keeps [[planet]]s [[orbit]]ing [[The Sun]] and [[The Moon]] [[orbit]]ing the [[Earth]].

==Key Stage 5==
===Meaning===
'''Newton's Law of Universal Gravitation''' states that the [[force]] between two [[object]]s is [[Directly Proportional|directly proportional]] to the product of their [[mass]]es and [[Inversely Proportional|inversely proportional]] to the square of the [[distance]] between them.

===About Newton's Law of Universal Gravitation===
: '''Newton's Law of Universal Gravitation''' can be used to calculate the [[magnitude]] of the [[force]] acting between two [[mass]]es.
: '''Newton's Law of Universal Gravitation''' has a similar form to [[Coulomb's Law]] in that both are given with a constant multiplied by a product of some physical property ([[Electrical Charge|charge]] and [[mass]]) and [[Inversely Proportional|inversely proportional]] to the square of the [[distance]] between [[particle]]s.

===Equation===
<math>F=-G \dfrac{m_1m_2}{r^2}</math>

Where;

<math>F</math> = The [[force]] acting between the [[Electrical Charge|charged particles]]

<math>G</math> = The [[Gravitational Constant]] (<math>6.67\times10^{-11}</math>)

<math>m_1</math> = The [[mass]] of one [[object]].

<math>m_2</math> = The [[mass]] of the second [[object]].

<math>r</math> = The [[distance]] between the [[Centre of Mass|centre of mass]] of each [[object]].

The definition can be derived from the equation by considering;

<math>-G</math> is a constant so the left hand side and right hand side are [[proportional]].

<math>m_1m_2</math> is the product of the [[mass]]es.

<math>\dfrac{1}{r^2}</math> is the the [[Inversely Proportional|inverse]] of the square of the [[distance]].

Therefore;

<math>F\propto\dfrac{m_1m_2}{r^2}</math>