force and breaking

• What should you be able to describe by the end of the video on vehicle braking?

  The energy changes during braking and the potential dangers of large decelerations
• What are the components of a car's stopping distance?

  The stopping distance consists of thinking distance plus braking distance
• How does the speed of a car affect its braking distance?

  If the speed of the car increases, the braking distance increases significantly
• What is the formula for calculating kinetic energy?

  Kinetic energy = $\frac{1}{2} \times \text{mass} \times \text{velocity}^2$
• Why is it important to learn the kinetic energy formula for the exam?

  Because it is not provided in the exam
• How does the kinetic energy change if the velocity of a car is doubled?

  The kinetic energy quadruples when the velocity is doubled
• What happens to the kinetic energy of a car when it brakes to a stop?

  All of the kinetic energy is converted into other forms of energy
• What form of energy is produced in the brakes during braking?

  The kinetic energy is converted to thermal energy in the brakes
• What effect does a large braking force have on a vehicle?

  A large braking force causes rapid deceleration and can lead to brake overheating
• What can happen if the brakes overheat?

  The driver may lose control of the vehicle
• What is the mass of the car used in the example for calculating forces during deceleration?

  1000 kilograms
• What is the initial velocity of the car in the example?

  The initial velocity is 30 meters per second
• How long does it take for the car to decelerate to zero in the example?

  It takes 10 seconds to decelerate to zero
• How do you calculate the acceleration of the car in the example?

  Acceleration = $\frac{\text{change in velocity}}{\text{time}} =$$\frac{30 \text{ m/s} - 0 \text{ m/s}}{10 \text{ s}} =$$3 \text{ m/s}^2$
• What is the force needed for the deceleration of the car in the example?

  Force = mass × acceleration = $1000 \text{ kg} \times 3 \text{ m/s}^2 =$$3000 \text{ N}$
• What are the potential dangers of large decelerations in vehicles?

  • Rapid deceleration can lead to loss of control
  • Overheating of brakes
  • Increased stopping distance
• How can you estimate the forces involved in the deceleration of vehicles on public roads?

  1. Identify the mass of the vehicle
  2. Determine the initial and final velocities
  3. Calculate the acceleration
  4. Use the formula: Force = mass × acceleration