Friction is an important force that affects how we design cars and machines.

Types of Friction:

• Static Friction: This type of friction keeps things still when they’re not moving.
• Kinetic Friction: This happens when two surfaces slide against each other.

Why Friction Matters in Design:

• Helps with traction: Cars need a friction level between $0.3$ and $0.6$ to speed up and stop safely.
• Influences fuel use: Too much friction can make cars use up to $15\%$ more fuel.

How We Use Friction in Machines:

• To keep machines running smoothly, we use bearings and lubricants. These help lessen unwanted friction, making everything work better.

Knowing about friction helps us make cars and machines safer, more efficient, and better at doing their jobs.