Force and Braking

• What are the potential dangers of large decelerations?

  Loss of control and brake overheating
• What is the stopping distance of a car composed of?

  Thinking distance plus braking distance
• How does speed affect braking distance?

  Higher speed increases braking distance significantly
• How does kinetic energy change with velocity?

  Kinetic energy depends on the velocity squared
• What is the formula for calculating kinetic energy?

  Kinetic energy = $\frac{1}{2}mv^2$
• What happens to kinetic energy when the velocity of a car doubles?

  Kinetic energy quadruples
• What happens to kinetic energy when a car brakes?

  Kinetic energy converts to thermal energy
• What causes the temperature of brakes to increase during braking?

  Conversion of kinetic energy to thermal energy
• What is required to stop a car traveling at high speeds?

  A large braking force is needed
• What can a large braking force cause?

  Brakes to overheat and loss of control
• What is the final speed of the car after deceleration?

  Zero meters per second
• How do you calculate the force needed for deceleration?

  Multiply mass by acceleration
• What is the acceleration of the car during deceleration?

  3 meters per second squared
• How long does it take for the car to decelerate to zero?

  Ten seconds
• What force is needed for the car's deceleration?

  3000 Newtons
• What are the energy changes during vehicle braking?

  • Kinetic energy converts to thermal energy
  • Brakes heat up due to energy conversion
  • Loss of kinetic energy slows the vehicle
• What factors affect the braking force needed to stop a vehicle?

  • Vehicle speed
  • Vehicle mass
  • Desired stopping distance
• How do you estimate forces involved in vehicle deceleration?

  1. Identify vehicle mass
  2. Determine initial and final velocities
  3. Calculate acceleration
  4. Use force = mass × acceleration