Difference between revisions of "Speed"
(Created page with "How fast something is moving, measured in metres per second.") |
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− | + | ==Key Stage 3== | |
+ | ===Meaning=== | ||
+ | [[Speed]] is how fast something is moving, [[measure|measured]] in [[Metres per Second|metres per second]]. | ||
+ | |||
+ | ===About Speed=== | ||
+ | : The scientific [[unit]]s of [[speed]] are [[Metres per Second]]. | ||
+ | : [[Speed]] is commonly measured in the [[unit]]s of [[Miles per Hour]], but this is not a scientific [[unit]]. | ||
+ | : Other [[unit]]s of [[speed]] can be given by the [[unit]]s of [[distance]] used and the [[unit]]s of [[time]] used in the calculation of [[speed]]. | ||
+ | : [[Speed]] can be found by [[measuring]] the [[distance]] travelled by an [[object]] in a given [[time]]. | ||
+ | |||
+ | ===Equation=== | ||
+ | :<math>Speed = {\tfrac{distance}{time}} </math> | ||
+ | :<math>s = {\tfrac{D}{t}} </math> | ||
+ | Where: | ||
+ | : s = Speed | ||
+ | : D = Distance | ||
+ | : t = Time | ||
+ | |||
+ | ===Example Calculations=== | ||
+ | {| class="wikitable" | ||
+ | |- | ||
+ | | style="height:20px; width:300px; text-align:center;" |'''A person jogs 300 [[metre]]s in 120 [[second]]s. Calculate the speed of the jogger.''' | ||
+ | | style="height:20px; width:300px; text-align:center;" |'''A racing car travels 500 [[metre]]s in 10 [[second]]s. Calculate the speed of the racing car.''' | ||
+ | |- | ||
+ | | style="height:20px; width:300px; text-align:left;" | | ||
+ | distance = 300[[m]] | ||
+ | |||
+ | time = 120[[s]] | ||
+ | |||
+ | <math>Speed = {\tfrac{distance}{time}} </math> | ||
+ | |||
+ | <math>Speed = {\tfrac{300}{120}} </math> | ||
+ | |||
+ | <math>Speed = 2.5m/s </math> | ||
+ | | style="height:20px; width:300px; text-align:left;" | | ||
+ | distance = 500[[m]] | ||
+ | |||
+ | time = 10[[s]] | ||
+ | |||
+ | <math>Speed = {\tfrac{distance}{time}} </math> | ||
+ | |||
+ | <math>Speed = {\tfrac{500}{10}} </math> | ||
+ | |||
+ | <math>Speed = 50m/s </math> | ||
+ | |- | ||
+ | | style="height:20px; width:300px; text-align:center;" |'''A [[horse]] takes 20 [[minute]]s to trot 2.4 [[kilometre]]s. Calculate the speed of the [[horse]] in [[Metres per second|metres per second]].''' | ||
+ | | style="height:20px; width:300px; text-align:center;" |'''The International Space Station takes 92 [[minute]]s to orbit the Earth once travelling 42,000 [[kilometre]]s. Calculate the speed of the ISS.''' | ||
+ | |- | ||
+ | | style="height:20px; width:300px; text-align:left;" | | ||
+ | distance = 2.4[[km]] = 2400[[m]] | ||
+ | |||
+ | time = 20[[min]] = 1200[[s]] | ||
+ | |||
+ | <math>Speed = {\tfrac{distance}{time}} </math> | ||
+ | |||
+ | <math>Speed = {\tfrac{2400}{1200}} </math> | ||
+ | |||
+ | <math>Speed = 2m/s </math> | ||
+ | | style="height:20px; width:300px; text-align:left;" | | ||
+ | distance = 42,000[[km]] = 42,000,000[[m]] | ||
+ | |||
+ | time = 20[[min]] = 5400[[s]] | ||
+ | |||
+ | <math>Speed = {\tfrac{distance}{time}} </math> | ||
+ | |||
+ | <math>Speed = {\tfrac{42000000}{5400}} </math> | ||
+ | |||
+ | <math>Speed = 7608.7m/s </math> | ||
+ | |||
+ | <math>Speed \approx 7600m/s </math> | ||
+ | |} |
Revision as of 17:47, 2 December 2018
Key Stage 3
Meaning
Speed is how fast something is moving, measured in metres per second.
About Speed
- The scientific units of speed are Metres per Second.
- Speed is commonly measured in the units of Miles per Hour, but this is not a scientific unit.
- Other units of speed can be given by the units of distance used and the units of time used in the calculation of speed.
- Speed can be found by measuring the distance travelled by an object in a given time.
Equation
\[Speed = {\tfrac{distance}{time}} \] \[s = {\tfrac{D}{t}} \] Where:
- s = Speed
- D = Distance
- t = Time
Example Calculations
A person jogs 300 metres in 120 seconds. Calculate the speed of the jogger. | A racing car travels 500 metres in 10 seconds. Calculate the speed of the racing car. |
distance = 300m time = 120s \(Speed = {\tfrac{distance}{time}} \) \(Speed = {\tfrac{300}{120}} \) \(Speed = 2.5m/s \) |
distance = 500m time = 10s \(Speed = {\tfrac{distance}{time}} \) \(Speed = {\tfrac{500}{10}} \) \(Speed = 50m/s \) |
A horse takes 20 minutes to trot 2.4 kilometres. Calculate the speed of the horse in metres per second. | The International Space Station takes 92 minutes to orbit the Earth once travelling 42,000 kilometres. Calculate the speed of the ISS. |
\(Speed = {\tfrac{distance}{time}} \) \(Speed = {\tfrac{2400}{1200}} \) \(Speed = 2m/s \) |
distance = 42,000km = 42,000,000m \(Speed = {\tfrac{distance}{time}} \) \(Speed = {\tfrac{42000000}{5400}} \) \(Speed = 7608.7m/s \) \(Speed \approx 7600m/s \) |