The Principles of Forces and Motion to the Safe Stopping of Vehicles

The Principles of Forces and Motion to the Safe Stopping of Vehicles

Understand the Importance of Forces in Motion

• Newton’s first law says an object will remain at rest or in motion unless acted upon by a net force. This explains the need for a force to stop a moving vehicle.
• Newton’s second law shows that the force needed depends on the mass of the vehicle and its deceleration. A large vehicle or high deceleration requires a large stopping force.

Recognize the Role of Friction

• Friction between the vehicle’s tyres and the road helps to provide the force needed to stop.
• Wet or icy conditions reduce friction, increasing stopping distances.
• Tyre conditions also affect friction. Worn tyres have less grip and increase stopping distance.

Learn About Stopping Distances

• The stopping distance of a vehicle is the sum of the thinking distance and the braking distance.
• The thinking distance is the distance a vehicle travels in the time it takes the driver to react.
• The braking distance is the distance a vehicle travels under the braking force.
• Both distances increase with speed, meaning faster vehicles have longer stopping distances.

Analyze the Influence of Vehicle Conditions

• Brake conditions can greatly affect stopping distance. Well-maintained brakes can apply more force and reduce stopping distance.
• Heavy loads increase a vehicle’s mass, as per Newton’s second law, increasing the force needed to stop and therefore the stopping distance.

Consider the Impact of Driver Factors

• Alcohol, drugs and fatigue can impair a driver’s reaction time, increasing the thinking distance and overall stopping distance.
• Distractions, such as mobile phones, can also increase reaction times.