Final answer:
To draw a free-body diagram for a car on a horizontal road, represent the car as a dot. Extend vectors from the dot to represent the weight (downward), normal force (upward), applied force (direction of motion), and frictional force (opposite direction). The applied and frictional forces should balance if the car is moving at a constant velocity, indicating dynamic equilibrium.
Step-by-step explanation:
To depict a car moving along a horizontal road using a free-body diagram, start by drawing a dot to represent the car's center of mass. From this dot, you'll extend vectors that represent all the forces acting on the car. In the case of a car on a horizontal road, the following forces need to be included:
- A downward vector representing the weight of the car, labeled w.
- An upward vector representing the normal force exerted by the road on the car, labeled N. The normal force is equal in magnitude and opposite in direction to the weight, assuming the car is not accelerating vertically.
- A vector in the direction of the car's motion representing the applied force from the car's engine, labeled Fapp.
- A vector opposite to the car's direction of motion representing the frictional force due to the road's surface, labeled f.
Other potential forces, such as air resistance, can also be represented by vectors if they are significant. Friction is the force that opposes the forward motion of the car. If the car is moving at a constant velocity, the applied force and frictional force should be of equal magnitude and opposite direction, illustrating dynamic equilibrium.
For any other forces that may be acting at an angle, such as on a banked curve, those forces would need to be broken down into their horizontal and vertical components on the free-body diagram.