Speed and Velocity

Speed and Velocity

1. Speed = distance/Time

2. If an object is speeding up it is accelerating

3. If an object is slowing down it is decelerating

4. A speed tells us how fast an object is moving

   • 20km/h

5. Velocity

   • Velocity tells us how fast and in which direction an object is moving
     • e.g 20km/h northwards

6. Distance Time graphs

   • When an object is stationary, the line on the graph is horizontal
   • When an object is moving at a steady speed, the line on the graph is straight, but diagonal.
   • Note that the steeper the line, the greater the speed of the object.
   • yaxis = distance
   • x axis = time

7. Measures of speed

   • m/h
     • Miles per hour
   • km/h
     • Kilometres per hour
   • m/s
     • Metres per second

8. Speed Time graphs

   • When an object is moving with a constant speed, the line on the graph is horizontal.
   • When an object is moving with a constant acceleration, the line on the graph is straight, but diagonal.
   • When an object is moving with a constant deceleration, the line on the graph is straight, but diagonal (sloping down).
   • y axis = speed
   • x axis= time