Difference between revisions of "Gravity"
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: [[Gravity]] is a constant [[force]] directed to the centre of a [[massive]] [[object]]. | : [[Gravity]] is a constant [[force]] directed to the centre of a [[massive]] [[object]]. | ||
: [[The Moon]] feels a [[force]] pulling it towards the centre of the [[Earth]]. The [[Earth]] feels a [[force]] equal in [[magnitude]] but opposite in direction to that of [[The Moon]]. | : [[The Moon]] feels a [[force]] pulling it towards the centre of the [[Earth]]. The [[Earth]] feels a [[force]] equal in [[magnitude]] but opposite in direction to that of [[The Moon]]. | ||
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| + | |[[File:Orbit1.gif|center|400px]] | ||
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| + | | style="height:20px; width:400px; text-align:center;" |The [[planet]]s are pulled towards the [[sun]] by [[gravity]]. | ||
Revision as of 08:42, 2 November 2018
Contents
Key Stage 2
Meaning
Gravity is a force that causes all objects to be attracted to each other.
About Gravity
- Gravity is a non-contact force.
- Gravity affects all objects.
- Gravity pulls us down towards the centre of the Earth.
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| If person A drops the cog it will fall towards the centre of the Earth. If person B drops the spanner it will fall towards the centre of the Earth. |
 |
| The planets are pulled towards the sun by gravity. |
Key Stage 3
Meaning
Gravity is a force that causes all objects with mass to be attracted to each other.
About Gravity
- Gravity is a force so it is measured in Newtons.
- Gravity is a non-contact force because it can act without objects touching.
- All objects are affected by gravity.
- Gravity is the force that pulls objects to the ground.
- Isaac Newton was the first to realise that gravity is the force that holds the planets in orbit around the Sun.
- The force of gravity between two objects is always equal in magnitude but opposite in direction.
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| Object A has 1kg of mass and is attracted to object B. Object B has 2kg of mass and is attracted to object A. The force acting on object A is the same as the force on object B. |
Falling
Energy Transfers
Accelerating
- When an object accelerates towards the ground energy is transferred from the gravitational potential energy store of the object to the kinetic energy store of the object.
Decelerating
- When an object decelerates away from the ground energy is transferred from the kinetic energy store of the object to the gravitational potential energy store of the object.
Forces
Accelerating
- When an object accelerates towards the ground gravity is causing a mechanical energy transfer.
Decelerating
- When an object decelerates away from the ground gravity is causing a mechanical energy transfer.
Orbits
- Newton was the first person to realise that objects were held in orbit by gravity which he explained in his Universal Theory of Gravitation.
- Moons orbit planets and planets orbit the stars due to gravity.
- Gravity is a constant force directed to the centre of a massive object.
- The Moon feels a force pulling it towards the centre of the Earth. The Earth feels a force equal in magnitude but opposite in direction to that of The Moon.
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| The planets are pulled towards the sun by gravity. |