Free Body Diagram quiz with answer key for AP Physics 1

📚 Quick Study Guide

• ⚖️ A free body diagram (FBD) is a visual representation of all the forces acting on an object.
• ➡️ Only forces acting on the object are included, not forces exerted by the object.
• 📍 Represent the object as a point mass.
• 🏹 Draw force vectors originating from the point mass, indicating direction and magnitude.
• 📝 Common forces: Gravity ($F_g = mg$), Tension ($T$), Normal Force ($F_N$), Friction ($F_f$), Applied Force ($F_a$).
• 📐 Choose a coordinate system to resolve forces into components.
• 💡 Newton's Second Law: $\sum F = ma$ (The net force equals mass times acceleration).

Practice Quiz

1. A block of mass $m$ is resting on a horizontal surface. Which of the following free body diagrams correctly represents the forces acting on the block?
   1. Only a downward force of gravity.
   2. An upward normal force and a downward force of gravity.
   3. An upward normal force only.
   4. A downward force of gravity and a horizontal applied force.
2. A box is being pulled to the right across a rough surface at a constant velocity. Which of the following forces must be included in the free body diagram?
   1. Applied force, gravity, and normal force.
   2. Applied force, gravity, normal force, and kinetic friction.
   3. Applied force and kinetic friction only.
   4. Gravity and normal force only.
3. A ball is thrown upwards. Ignoring air resistance, what forces act on the ball at its highest point?
   1. An upward force and a downward force of gravity.
   2. Only a downward force of gravity.
   3. No forces act on the ball.
   4. An upward force only.
4. A block is sliding down a frictionless inclined plane. Which forces should be included in the free body diagram?
   1. Gravity and normal force.
   2. Gravity, normal force, and friction.
   3. Gravity only.
   4. Normal force only.
5. A lamp is hanging from a cord suspended from the ceiling. What forces act on the lamp?
   1. Tension and gravity.
   2. Tension only.
   3. Gravity only.
   4. Tension and applied force.
6. A car is accelerating forward. What forces act on the car?
   1. Applied force and gravity.
   2. Applied force, gravity, and normal force.
   3. Applied force, gravity, normal force, and friction.
   4. Gravity and normal force only.
7. A book is at rest on an incline. What forces act on the book?
   1. Gravity and normal force.
   2. Gravity, normal force, and static friction.
   3. Gravity only.
   4. Normal force and kinetic friction.