Speed, distance and time/ Velocity and acceleration.

we can calculate speed using the formula.
    

•     speed = distance 
                      time (seconds)                        

Speed can have different units.

• Miles per hour (mph)
• kilometers per hour
• knotts (used on boats)
• meters per second (m/s)
• meters per hour (m/h)

Velocity is "speed in a given direction"

Acceleration is a measure of how quicly velocity changes.

Acceleration = change in velocity
 in (m/s)                time taken

example: A cyclist accelerates from 0 to 10m/s in 5 seconds, what is her acceleration?

                      a = v-u   = 10-0   =   10  = 2m/s
                              t           5           5

Any object that is moving has kinetic energy.
Kinetic energy increases when: 

• velocity increases
• mass increases

Example:A ball thrown into the air gradually its kinetic energy
               is transferred to gravitational potential energy.

              As the ball falls back down its gravitational potential
              energy is transferred into kinetic.

             when a car brakes to slow down, kinetic energy is tranformed
             into thermal energy.