Key Idea 1

Speed Formulas: Distance / Speed = Time
Distance / Time = Speed Speed x Time = Distance

Acceleration Formulas: Change in Velocity / Time Taken = Acceleration
Change in Velocity / Acceleration = Time Taken
Acceleration x Time Taken = Change in Velocity

Energy is measured in Joules. One joule is the energy used in a force of one Newton over a distance of one metre.

Distance is measured in metres, kilometres, centimetres etc
Speed/Velocity is measured in m/s, km/h etc
Time is measured in seconds, minutes, hours etc
Acceleration is measured in m/s/s, km/h/h etc

To calculate how much energy you burn, you use this speed formula: 1/2 x mass x speed squared = joules per second burned.

For example, if I ran 200 metres in 40 seconds, then my speed would be 200 / 40 = 5 m/s. If I weighed 60 kgs I would be burning 1/2 x 60 x 5 squared = 750 J per second. 750 J x 40 (time) = 30000 J burned, which is 30 kJ.

Bananas are 378 kJ, so I would need to run for 504 seconds which is 8.4 minutes.

Hannah and I decided to investigate whether height influences speed and compared speed to joules per second. We did this by measuring the height and weight of our classmates and getting them to run 20 metres as fast as they could.

This graph shows the comparison between height and speed.

http://imgur.com/d9bOzxz

As a general rule, taller people are faster than shorter people. I think this is because taller people generally have longer legs and so can take longer strides. The one outlier of this rule is Daniel (bottom right).

This second graph shows the comparison between joules per second burned and speed. Oddly enough it looks like a running girl.

http://imgur.com/6RuPO2k

The data points that make out the "hair" are heavy people, because people with more mass burn more energy.