Forces

• What are forces?

  Forces can make things accelerate or decelerate depending on the direction or shape
• What are some forces referred to as?

  Contact (c) or non contact (nc)
• What happens when several forces act on an object?

  We need to find the combined force taking into account both the size and direction of each force
• What is a combined force called?

  A resultant force
• What are forces measured in?

  Forces are measured in Newtons (N)
• Speed or velocity 


  distance/time v=d/t (units=m/s)
• Acceleration

  change in speed(velocity)/time taken a=v-u/t
• Force

  mass x acceleration (ma)
• Hooke's Law

  Spring constant x extension (F=ke)
• Stopping distance

  Thinking distance + braking distance
• Typical human reaction time

  0.2-0.9 seconds