Final answer:
The efficiency of a bus's brakes should be checked before driving over 50 km/h to ensure safe stopping distances and reduce the risk of accidents.
Step-by-step explanation:
The efficiency of a bus's brakes should be checked before driving over 50 km/h. This is because at high speeds, it takes longer for a vehicle to come to a complete stop, and faulty brakes could increase the stopping distance. By checking the brakes before reaching this speed, the driver can ensure that they are functioning properly and reduce the risk of an accident.
One way to check the efficiency of the bus's brakes is by driving the bus at a constant speed of 50 km/h and then applying the brakes until the bus comes to a complete stop. The distance it takes for the bus to stop can be measured and compared to the expected stopping distance. If the actual stopping distance is significantly longer, it may indicate that the brakes are not operating efficiently.
Additionally, regular maintenance and inspections should be conducted to ensure that the brakes are in good working condition. This includes checking brake fluid levels, brake pad wear, and any signs of damage or corrosion.