A parked automobile slips out of gear, rolls unattended down a slight incline, and then along a level road until it hits a stone wall. Draw an FBD to show the forces acting on the car while it is in contact with the wall.

To draw the FBD, we need to identify all the forces acting on the car when it is in contact with the wall. We have the following forces: 1. Gravitational force (weight): This is the force due to gravity and acts vertically downwards on the car. 2. Normal force: This is the force exerted by the ground on the car, to counterbalance the gravitational force, acting perpendicular to the surface the car is on. 3. Friction: The force between the car's tires and the ground, opposing the car's movement, acting parallel to the ground. 4. Impact force from the wall: This is the force exerted by the wall on the car, pushing the car back as a reaction to the car's impact on the wall.

In order to draw the FBD, we need to establish a coordinate system. Place the origin at the center of mass of the car with the positive x-axis to the right and the positive y-axis upwards.

Now we can draw the FBD with all the forces acting on the car while it is in contact with the wall: 1. Gravitational force (weight): Draw a vertical arrow pointing downwards, labeled as F_g, from the origin. 2. Normal force: Draw an arrow from the origin perpendicular to the ground (vertical), pointing upwards, labeled as F_N. 3. Friction: Draw an arrow from the origin parallel to the ground (horizontal) pointing to the left (opposite to the car's original movement), labeled as F_f. 4. Impact force from the wall: Draw an arrow from the origin horizontally to the right, labeled as F_w. In this FBD, all the forces acting on the car are now represented. It shows the force of gravity pulling the car downward, the normal force counteracting the gravitational force, the friction force opposing the movement of the car, and the wall's impact force pushing the car back.