Topic 9 - Free Body Diagrams and Forces

Question 1

Free Body Diagrams (FBD)

extremely important in Physics

Answer 1

Sometimes, there are many forces acting on an object and FBD’s needs to be very detailed to use the proper calculations, especially when angles are involved

Question 2

Case 1: Level Surface

Normal Force (𝑛 ⃑)

Answer 2

The component of the contact force that is perpendicular to the contact surface

Question 3

Case 2: Level Surface with Applied Force

Normal Force (𝑛 ⃑)

• What happens if the block is now being pushed/pulled?

Answer 3

Question 4

Case 3: Level Surface with Acceleration

Normal Force (𝑛 ⃑)

• What happens if we have a level surface, but it’s under acceleration? Like an elevator?

Answer 4

Question 5

Case 4: On a Slope

Normal Force (𝑛 ⃑)

• Be careful with normal force when there is slope

Answer 5

Remember, normal force is the force that the surface pushes back on….perpendicularly

Question 6

Kinetic Friction

Answer 6

A friction force that opposes the direction of motion during motion

Question 7

Static Friction

When we want to move something on a surface, there’s resistance

Answer 7

• The rougher the surface, the harder it is to push something – but if we push hard enough, it could move!
• The tipping point between being stuck and moving is called a critical value (max. static friction force)

Question 8

Problem Solving Approach to 1D Kinematics

Answer 8

Question 9

Key Equations and Concepts

Answer 9