Speeding Up

Speeding Up

1. Definition

   • Speed is how fast something moves.
     • Speed tells you distance traveled in a certain time.
     • average speed= distance (divided by) time

2. Units

   • Units of speed include: m/s, mph, and km/h.

3. Balanced Forces

   • When all forces acting on an object balance then it can be:
     • Moving at a constant speed in a straight line.
     • Stationary.

4. Unbalanced Forces

   • An unbalanced force in the direction of motion causes something to speed up.
     • When something speeds up we say it accelerates.
     • An unbalanced force acting in the opposite direction to motion causes something to slow down.
       • When something slows down we say it decelerates.

5. Drag

   • When something moves through air or water there are drag (friction) forces.
     • The size of the drag in air or water depends on the speed.
     • Streamlining can be used to reduce the drag in air or water.