Terminal velocity

• Friction is always there to slow things down

  • If an object has no fore propelling it along it wil always sIow down and stop because of friction
  • Friction always acts in the opposite direction to movement
  • to travel at a steady speed, the driving force needs to balance out the frictional forces
  • you can reduce friction by using a lubricant
• Drag increases as speed increases

  • Drag is the resistance? you get in a fluid
  • Air resistance is a type of drag
  • To reduce drag, keep the object streamlined
  • This is where the object is designed to allow fluid to flow easily across it, reducing drag. parachutes work in the opposite way
  • Frictional forces in fluids increase with speed
• objects falling through fluids reach a terminal velocity

  • when a falling Object first Sets Off, the force of gravity is much more than the frictional force slowing it down, so it accelerates
  • As the speed increases, the friction builds up
  • this gradually reduces the acceleration until eventually, the frictional force is equal to the accelerating force
  • It will have reached its maximum speed or terminal velocity and will fall at a Steady speed
• Terminal velocity depends on shape and area

  • less streamlined an object is the lower its terminal velocity
  • objects with large surface areas tend to have lower terminal velocities
  • so bigger objects are slower because there is more air resistance acting on them