When is friction considered unhelpful in a car?

Friction is a force that opposes motion, and it can play a beneficial role in many driving scenarios, such as accelerating or braking effectively. However, when a car is skidding on slick surfaces, friction becomes unhelpful.

In this context, skidding indicates a loss of control over the vehicle, typically due to insufficient friction between the tires and the road. This lack of effective friction means that the tires cannot grip the road adequately to maintain control, leading to potential accidents or unsafe driving conditions.

In contrast, when a car is accelerating, braking, or moving in a straight line under normal conditions, friction helps provide the necessary grip to control the vehicle, allowing for safe and effective driving. Thus, while friction is generally advantageous in these scenarios, it is during skidding on slippery surfaces that it fails to contribute positively to vehicle control.