Question

Refer to the first analogy and answer the following.

1)Gravel on slippery surface : increases friction :: _________: reduces friction

2) Wheels of a bag : rolling friction:: A box of books dragged on the floor :______.​

Answer 1

Answer:

Explanation:

1) When it rains, the water on a road causes a loss of friction. As tires move over a wet surface, the water fills in the tiny pits in the road surface, effectively smoothing out the surface. As a result, the normal heat and friction created is decreased, leading to a surface that is more slippery than when dry.

2) Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated