Forces and Motion

• Initially, when the skydiver jumps out of the plane he accelerates  towards the ground
•  What force opposes his motion towards the ground? Air resistance
•  As the velocity of the skydiver increases, his air resistance?

  Increases
• The skydiver reaches his terminal velocity. What does this mean?

  The speed of the skydiver when the air resistance equals his weight
• When the skydiver opens his parachute his air resistance

  increases
• The air resistance of the skydiver is now greater than his weight. His velocity


  decreases
•  As his velocity decreases, his air resistance starts to decrease
•  Once again he reaches a terminal velocity. It is lower than the terminal velocity he reached before the parachute was opened
• State the formula linking unbalanced force, mass and acceleration.


  Force= mass x acceleration
• What affects thinking distance? Consumption of alcohol by the driver.
• What affects both thinking distance and braking distance?


  Speed of the vehicle.
• stopping distance = thinking distance + braking distance