In which scenario would frictional force be at work?

Frictional force is present in scenarios where two surfaces are in contact and there is a tendency for movement between them. In the case of a car accelerating on a road, friction plays a crucial role in enabling the car's tires to grip the road surface, allowing it to accelerate without slipping.

When the car's engine generates power to turn the wheels, the tires push against the road. It is the friction between the tires and the road that provides the necessary force to move the vehicle forward. This frictional force helps prevent the tires from spinning freely and losing traction, which is essential for effective acceleration.

In contrast, the other scenarios lack the requisite conditions for frictional force to be significant. For example, an object sliding down a smooth hill would experience minimal friction if the surface is indeed smooth. A book sitting still on a table is affected by static friction, but does not involve any movement. Similarly, a rubber ball bouncing on a surface primarily involves elastic forces and momentum exchange rather than frictional force being at work in a significant manner.