Please refer to the attached photo for the following questions. The other two photos included are solely for the purpose of providing additional information about the topic.

Key Concepts, and Equations Concept Discussion Refers to a force that resist motion between material in Friction contact. Friction exist in all types of materials. Type of friction between solid surface for a. Static friction b. Kinetic friction or sliding friction c. Rolling friction Static friction - occurs in cases where friction is sufficient to prevent relative motion between the surfaces. Kinetic friction - present when there is a relative motion between the surfaces in contact. Rolling friction - occurs when one surface rotates as it moves over another without sliding nor slipping at the point or area of contact Fluid friction (drag force) - refers to the force that resist relative motion of an object through a fluid or of a fluid through another fluid. 23Laws of frictions a. Static friction is greater than kinetic friction in magnitude. . Friction acts parallel to the surfaces in contact and in a direction oppose motion. Friction cannot produce motion. Its main role is to oppose motion. e. Friction is independent to the area of contact and speed of sliding. d. Friction is proportional to the normal force e. Friction depends on the nature of surfaces in contact and condition of surfaces, that is whether the surfaces are rough, smooth, polished, or wet. Mathematically; Jamar - DAFN Where; Jomar - Maximum static friction Is - coefficient of static friction Fi - Normal Force Where; Jmar - Kinetic friction I - coefficient of kinetic friction Fri- Normal Force Coefficient of Friction between Materials Materials Static Kinetic Materials Static Kinetic Steel on steel 0.74 0.57 Tellon on steel 0.04 0.04 Aluminum on steel 0.61 1.47 Steel on air 0.001 0.001 Copper on steel 0.53 D. 36 Rubber on concrete 1.0 0.8 Brass on steel 0.51 0.44 Steel on ice 0.03 Zinc on cast iron 1.85 1.21 Tendon and sheath 0.013 Copper on cast iron 1.29 Lubricated bone joint 0.001 0.003 Glass on glass 0.94 0.40 Wood on wood 0.3 Copper on glass 0.68 0.53 Waxed wood on dry 0.04 Tellon on tellon 0.04 0.04 snowactivity Gen. Physics 12 Titanium Friction For number 1, please show your complete solution. For number 2 and 3, please explain it connected to topic which is friction. 1. Find the coefficient of friction on an unknown material with a static friction of 15.5 N and a normal force of 200 N. 2. What is easier to push, a wooden cabinet in a concrete flooring or a wooden cabinet in a tiled flooring? 3. Inside a motorcycle machine, the wheel and axle are subject to rust and corrosion that is why, mechanics time to time make sure to put some oil and other lubricants. What is the purpose of the oil and lubricants and why