Friction plays a crucial role in both propelling and slowing down a car. When a car accelerates, the engine generates power that is transferred to the wheels, creating friction between the tires and the road, which propels the vehicle forward. On slippery surfaces, such as ice, insufficient friction prevents effective acceleration, leading to loss of control. To slow down a car, brakes are applied, increasing friction between the brake pads and the wheels, which reduces speed. Understanding the dual role of friction is essential for safe driving and vehicle performance.