The monthly compound interest can be determined from the following formula:
Where A is the final amount after interest, P is the intital amount invested, r is the interest rate, n is number of times interest is compounded per year, and t is the time in years.
We need to express rate as abn equivalent decimal number:
The equation to find volume is V=r²h and you know all of your numbers other than h so you plug all that in. 100=3.14×2²×h → 100=3.14×4×h → 100=12.56×h → Divide 12.56 from both sides 100÷12.56=12.56×h÷12.56 → 7.96cm=h.