Question 1: Explain in your own words what is meant by 'braking distance' and how it differs from 'reaction distance'.

Answer: Braking distance is the distance a vehicle travels from the moment the brakes are applied until it comes to a complete stop. Reaction distance is the distance travelled from noticing the danger to applying the brakes.

Question 1: What force primarily acts to bring a moving vehicle to a stop during braking?

Answer: Friction between the brake pads and the wheels or brake disc.

Question 2: Describe how the mass of a vehicle affects its braking distance, assuming all other factors remain constant.

Answer: A heavier vehicle (greater mass) generally requires a longer braking distance because more force is needed to decelerate it at the same rate.

Question 1: Calculate the braking distance of a car travelling at 20 m/s that decelerates at 5 m/s². (Use the formula: s = v² / (2a)).

Answer: s = (20)^2 / (2 × 5) = 400 / 10 = 40 meters

Question 2: If a vehicle's initial speed is 15 m/s and it takes 6 seconds to come to rest, what is its average deceleration? (Use the formula: a = v / t).

Answer: a = 15 / 6 = 2.5 m/s²

Question 1: List three variables that could affect the outcome of a braking distance experiment, and specify whether each is a controlled, independent, or dependent variable.

Answer: Variables include: (1) Vehicle mass - independent variable; (2) Road surface friction - controlled variable; (3) Initial speed of vehicle - independent variable; (4) Braking force applied - controlled variable.

Question 2: Describe two safety precautions that should be taken when conducting a practical experiment related to braking distances.

Answer: Ensure the experiment is conducted in a controlled environment away from traffic, and use safety barriers or equipment to prevent accidents during testing.

Question 1: A vehicle travelling at 25 m/s takes 5 seconds to come to rest after applying the brakes. Calculate its deceleration and braking distance.

Answer: Deceleration: a = 25 / 5 = 5 m/s². Braking distance: s = v² / (2a) = 25² / (2 × 5) = 625 / 10 = 62.5 meters.

Question 2: In real-world road safety, why is it important for drivers to maintain a safe following distance, especially at high speeds?

Answer: Maintaining a safe following distance allows enough space for braking, reducing the risk of collisions if the vehicle ahead suddenly stops or slows down.

Question 1: Explain how increasing the initial speed of a vehicle affects its braking distance. Include the relevant physics principles and calculations to support your explanation.

Answer: Increasing the initial speed (v) of a vehicle significantly increases its braking distance because the braking distance (s) is proportional to the square of the speed (s = v² / 2a). For example, if the speed doubles, the braking distance increases fourfold, assuming constant deceleration. This is due to the kinetic energy (which depends on v²) needing to be dissipated by friction during braking. Therefore, higher initial speeds require longer distances to stop safely.