Recent content by slapshotphil

turns out i needed to calculate the volume of seawater by using the molar mass and the density rather than through pv=nrt

Homework Statement The annual world use of liquid hydrocarbon fuels for transportation purposes currently generates about 10^17 kJ. If we could instead run our transportation system by oxidizing hydrogen gas to gaseous water, we would likely have to obtain the hydrogen by electrolyzing water...

the sum of ri is... 1-rn 1-r but for the derivative of that i got (-nrn-1)(1-r) - (1-rn)(-1) (1-r)2 which is not the correct answer... any hints?

the sum starts at (i=1) and ends at (n)

how will finding the derivative of the sum help me find the formula for the sum?

Determine a formula for the sum of \sum iri-1 in terms of n and r. I am stuck on this, i don't understand what to do with the "i" infront of the ri-1i know that \sum ri-1 = (1-rn ) /1-r all sums are for an index of i=1 to n I...