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Created page with "==Key Stage 3== ===Meaning=== '''Decelerate''' means to slow down. ===About Deceleration=== : '''Deceleration''' is the opposite of acceleration. : '''Deceleration''' is..."
==Key Stage 3==
===Meaning===
'''Decelerate''' means to slow down.
===About Deceleration===
: '''Deceleration''' is the opposite of [[acceleration]].
: '''Deceleration''' is usually caused by [[Air Resistance|air resistance]], [[Water Resistance|water resistance]] or [[friction]].
==Key Stage 4==
===Meaning===
'''Deceleration''' is a negative [[acceleration]] in which the [[magnitude]] of the [[velocity]] decreases.
===About Deceleration===
: '''Deceleration''' is a [[vector]] because it has [[magnitude]] and direction.
: The direction of [[deceleration]] is opposite to the direction of motion of an [[object]].
===Rapid Deceleration===
: Rapid '''deceleration''' can be dangerous as the [[force]]s involved increase as the [[time]] taken to '''decelerate''' decreases.
The following equation shows how the [[force]] on an object during a '''deceleration''' is proportional to the change in [[momentum]] but inversely proportional to the [[time]] taken.
<math>F = \frac{m \Delta v}{t}</math>
Where:
<math>F </math> = The impact [[force]].
<math>m \Delta v</math> = The change in [[momentum]].
<math>t</math> = The time taken for the [[momentum]] to change.
: When vehicles crash there is rapid '''deceleration''' so vehicles are designed to spread the change in [[momentum]] over the longest time possible to reduce the [[force]]s acting on the passengers.
The features that vehicles have to increase the [[time]] and therefor decrease the '''deceleration''' [[force]]s are:
*Crumple zones - Vehicles are designed so that the front will get crushed during the crash rather than being solid. This allows the change in [[momentum]] to take longer.
*Air Bags - Car's are often fitted with bags that will suddenly inflate in a crash and then deflate as the passenger collides with it. This allows the passenger's change in [[momentum]] to take longer.
===Meaning===
'''Decelerate''' means to slow down.
===About Deceleration===
: '''Deceleration''' is the opposite of [[acceleration]].
: '''Deceleration''' is usually caused by [[Air Resistance|air resistance]], [[Water Resistance|water resistance]] or [[friction]].
==Key Stage 4==
===Meaning===
'''Deceleration''' is a negative [[acceleration]] in which the [[magnitude]] of the [[velocity]] decreases.
===About Deceleration===
: '''Deceleration''' is a [[vector]] because it has [[magnitude]] and direction.
: The direction of [[deceleration]] is opposite to the direction of motion of an [[object]].
===Rapid Deceleration===
: Rapid '''deceleration''' can be dangerous as the [[force]]s involved increase as the [[time]] taken to '''decelerate''' decreases.
The following equation shows how the [[force]] on an object during a '''deceleration''' is proportional to the change in [[momentum]] but inversely proportional to the [[time]] taken.
<math>F = \frac{m \Delta v}{t}</math>
Where:
<math>F </math> = The impact [[force]].
<math>m \Delta v</math> = The change in [[momentum]].
<math>t</math> = The time taken for the [[momentum]] to change.
: When vehicles crash there is rapid '''deceleration''' so vehicles are designed to spread the change in [[momentum]] over the longest time possible to reduce the [[force]]s acting on the passengers.
The features that vehicles have to increase the [[time]] and therefor decrease the '''deceleration''' [[force]]s are:
*Crumple zones - Vehicles are designed so that the front will get crushed during the crash rather than being solid. This allows the change in [[momentum]] to take longer.
*Air Bags - Car's are often fitted with bags that will suddenly inflate in a crash and then deflate as the passenger collides with it. This allows the passenger's change in [[momentum]] to take longer.