One of your classmates claims that the free body diagram for the skidding car above is incorrect. They think that it should have an arrow to represent the car's inertia, which keeps it moving to the left. Evaluate this claim.

To evaluate your classmate's claim, let's break down the components of a free body diagram and the concept of inertia:

1. Free Body Diagram Basics:

   • A free body diagram (FBD) is a graphical representation used to visualize the forces acting on an object.
   • It typically includes arrows to represent forces such as gravity, normal force, friction, and applied forces.

2. Inertia:

   • Inertia is a property of matter that describes an object's resistance to changes in its state of motion.
   • According to Newton's First Law of Motion, an object will remain at rest or in uniform motion unless acted upon by an external force.

3. Forces vs. Inertia:

   • Inertia itself is not a force; it is a property of the object.
   • Forces are vectors that can be represented in a free body diagram, while inertia is a scalar property that cannot be represented by an arrow.

4. Skidding Car Scenario:

   • For a skidding car, the relevant forces might include friction (opposing the direction of motion), gravity (acting downward), and the normal force (acting perpendicular to the surface).
   • The car's inertia explains why it continues to move in the absence of external forces, but it is not depicted as a force in the FBD.

5. Conclusion:

   • Your classmate's claim that the FBD should include an arrow for inertia is incorrect.
   • Inertia is not a force and therefore should not be represented by an arrow in a free body diagram.
   • The FBD should only include actual forces acting on the car, such as friction, gravity, and the normal force.

By understanding the distinction between forces and inertia, we can conclude that the free body diagram should not include an arrow for inertia.