Which two compounds are used in batteries? sulfuric acid and potassium hydroxide
ammonium hydroxide and nitric acid
potassium hydroxide and nitric acid
sulfuric acid and ammonium hydroxide

Sulfuric acid and potassium hydroxide.

Explanation:

These are the two compounds used in car batteries, hope this helps!

OK, so the downward force on the rock is mg (force of g) - 2.8N (force in opposite direction). since mg (9.6 kg*9.8 m/s^2)= 94.08 N, then mg-2.8= 91.28 N. That is your net force on the rock (or total force). And, since f=ma, a= f/m.
so, a= 91.28 N / 9.6 kg = 9.5 m/s^2.(final answer)