Difference between revisions of "Force"
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===Forces as Vectors=== | ===Forces as Vectors=== | ||
: [[Force]]s have both [[magnitude]] and direction so they are considered [[vector]]s. | : [[Force]]s have both [[magnitude]] and direction so they are considered [[vector]]s. | ||
+ | ====Forces on a Free Body Diagram==== | ||
: To show [[force]] [[vector]]s a [[Free Body Diagram]] can be used, this indicates the [[magnitude]] and direction of the [[force]]s. | : To show [[force]] [[vector]]s a [[Free Body Diagram]] can be used, this indicates the [[magnitude]] and direction of the [[force]]s. | ||
{| class="wikitable" | {| class="wikitable" | ||
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| style="height:20px; width:200px; text-align:center;" |This [[diagram]] shows an [[object]] with 4 [[force]]s with pairs acting in opposing directions. The [[Resultant Force|resultant force]] here is 1N [[horizontal]]ly to the right. | | style="height:20px; width:200px; text-align:center;" |This [[diagram]] shows an [[object]] with 4 [[force]]s with pairs acting in opposing directions. The [[Resultant Force|resultant force]] here is 1N [[horizontal]]ly to the right. | ||
|} | |} | ||
+ | ====Forces on a Scale Diagram==== | ||
+ | : [[Force]]s can be added using a [[Scale Diagram|scale diagram]]. |
Revision as of 11:24, 4 February 2019
Contents
Key Stage 2
Meaning
A force is something which can make an object; speed up, slow down or change shape.
- Noun: Force
About Forces
- A force can make an object speed up. When you let go of a pencil it will fall because a force called weight is making it speed up.
- A force can make an object slow down. When you roll a ball on the carpet it will slow down and stop because a force called friction has slowed it down.
- A force can change the shape of an object. When you tip a spoon of honey the honey will change shape and stretch because a force called weight pulls it into a long shape before dripping.
Key Stage 3
Meaning
A force is an influence that can change the speed, direction of motion or shape of an object.
About Forces
- The scientific units of force is the Newton (N). However, force can also be measured in pounds (lb) and ounces (Oz).
- Forces can be measured using a Newton Meter.
- Forces can be split into two groups, Contact Forces and Non-contact Forces.
Contact Forces | Non-contact Forces |
- Forces can cause an object to accelerate.
- A pair of opposing forces can twist, stretch or squash an object. This is known as deformation.
Force Arrows
- Forces can be represented in a diagram with arrows that show the magnitude and direction of the force. A bigger arrow means a bigger force.
A boat that is not moving. | A tennis ball falling. | A bowling ball moving to the right. |
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A submarine travelling to the left. | A plane flying to the right. | A car driving to the right. |
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Key Stage 4
Meaning
A force is a vector quantity can affect the speed, direction of motion or shape of an object.
About Forces
- The SI Unit of force is the Newton (N).
- A force can be measured using a Newton Meter.
- Forces follow Newton's Third Law which states that if an object 'A' exerts a force on object 'B'; then object 'B' will exert a force on object 'A' which is equal in magnitude but opposite in direction to the original force. These are sometimes called an action force and a reaction force. This means:
- When you push a wall with a force of 5N (Action Force), the wall pushes back with a force of 5N (Reaction Force).
- If 'head' a football with a force of 10N then your head provides a force of 10N (Action Force) to the ball and the ball provides a force of 10N to your head (Reaction Force).
- Forces can cause an object to accelerate.
- A pair of opposing forces applied to different parts of an object can twist, stretch or squash the object. This is known as deformation.
Forces as Vectors
Forces on a Free Body Diagram
- To show force vectors a Free Body Diagram can be used, this indicates the magnitude and direction of the forces.
This diagram shows an object with a vector force of 5N magnitude directed horizontally to the right. | This diagram shows an object with 2 forces of 5N magnitude in opposite directions, vertically. | This diagram shows an object with 2 forces. One of 5N magnitude directed horizontally to the right, the other 3.5N directed vertically down. | This diagram shows an object with 4 forces with pairs acting in opposing directions. The resultant force here is 1N horizontally to the right. |
Forces on a Scale Diagram
- Forces can be added using a scale diagram.