Terminal Velocity and Reaction Times

• What is terminal velocity?

  The constant speed of a falling object
• What is friction?

  A force opposing an object's motion
• In which direction does friction act?

  Opposite to the direction of movement
• What is drag?

  The frictional force caused by fluids
• What causes drag on a moving object?

  Any fluid, such as air resistance
• What happens to an object when the force of gravity is greater than the frictional force?

  The object accelerates downwards
• How do parachutes affect terminal velocity?

  They increase air resistance, reducing speed
• What is a typical reaction time?

  Between 0.2 and 0.0 seconds
• What are three factors affecting reaction times?

  Distractions, speed, and distance fallen
• What are the steps in the Ruler Drop Test?

  1. Hold ruler with zero between fingers
  2. Drop ruler without warning
  3. Catch it as quickly as possible
  4. Measure distance fallen to calculate reaction time
• How does speed affect frictional forces from fluids?

  Frictional forces increase with speed
• What is the relationship between stopping distance and speed?

  Stopping distance increases with speed
• What two factors affect stopping distance?

  Speed and driver reaction time
• What happens when brakes are applied to a vehicle?

  Friction causes work to be done
• What is the principle of conservation of momentum?

  Momentum remains constant in a closed system
• What happens to momentum during a collision?

  Momentum is conserved in the system