Answer:
I think Albert Einstein invented physics.
Explanation:
Iam soory if Iam wrong.
Answer:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.
Coefficient of friction, ratio of the frictional force resisting the motion of two surfaces in contact to the normal force pressing the two surfaces together. It is usually symbolized by the Greek letter mu (μ). Mathematically, μ = F/N, where F is the frictional force and N is the normal force.
Refrigerator was what is commonly used today. We do dry foods and salt cure but that is not done on a daily basis