Rocks A and B are located at the same height on top of a hill. The mass of rock A is twice the mass of rock B. How does the potential energy of rock B compare to that of rock A? A. Rock B has the same potential energy as rock A.
B. Rock B has one-quarter the potential energy of rock A.
C. Rock B has one-half the potential energy of rock A.
D. Rock B has twice the potential energy of rock A.

Option C

Explanation:

Let the potential energy of rock A be represented as Pa

And the potential energy of rock B be represented as Pb

Pa = ma * g * h

Pb = mb * g*h

ma = 2 * mb

Thus, Pa = 2 mb * g*h

Pa/Pb = 2 mb * g*h/mb * g*h

Pa/Pb = 2

Pa = 2 * Pb

The energy pf rock A is two times the energy of rock B.

OR

Pb = Pa/2

Hence, option C is correct

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

the answer your looking for is c. : )