Answer to Question #276398 in Physics for Rakibul

Question

(a) Define friction.

(b) Explain the static and kinetic friction with suitable diagrams. A large block of ice

is being pulled across a frozen lake. The block of ice has a mass of 250 kg. The

coefficient of friction between two ice surfaces is small: μk = 0.05. What is the

force of friction that is acting on the block of ice?

(c) Why friction is importance in terms of physics and engineering studies.

Answer 1

Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

In static friction, the frictional force resists force that is applied to an object, and the object remains at rest until the force of static friction is overcome. In kinetic friction, the frictional force resists the motion of an object.

$$F=0.05(250)(9.8)=123\ N$$

Engineers need to understand the force of friction so that they can design safe roads, tires, cars and brakes. Engineers also try to reduce the force of friction between moving mechanical parts so that they will last longer.