Alida runs her toy car on a dry marble floor, wet marble floor, newspaper and towel saw spread on the floor. The force of friction
acting on the car on different surfaces in increasing order will be
wet marble floor, dry marble floor, newspaper,
towel
newspaper, towel, dry marble floor, wet marble
floor,
towel
, newspaper, dry marble floor, wet marble
floor
wet marble floor, dry marble floor, towel,
newspaper

wet marble floor, dry marble floor, newspaper,

wet marble floor, dry marble floor, newspaper,towel

This is the answer

A.

Explanation:

Force of friction depends on the nature of surface in contact. The rougher the surface, the more is the friction between the surfaces in contact and vice-versa. Roughness present in the given surfaces can be arranged in an ascending order as wet marble floor, dry marble floor, newspaper and towel.

Hence, the correct sequence of these surfaces when arranged according to the increase in the force of friction acting on the car is - wet marble floor, dry marble floor, newspaper and towel.

answer: b has a great day

explanation:

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals