Science & Mathematics - 10 November 2007

If I invested $6000 for one year, part of it at 9% and the rest at 11%. At the end of the year I earned $624 in interest. How much of the $6000 did I invest at each rate?

2007-11-10 01:25:20 · 3 answers · asked by donna g 1 in Mathematics

No, im not asking what time it is lol, im asking, what actually is time, how does it work and how do we know it even exists, how did the first ever person to make a clock decide what time it was? difficult question i know, it makes you think, so whats your thoughts?

2007-11-10 01:23:49 · 15 answers · asked by Rik M 1 in Astronomy & Space

2007
- 22
____


and can you show me how you did it?

2007-11-10 01:01:53 · 8 answers · asked by Anonymous in Mathematics

2007-11-10 00:59:01 · 14 answers · asked by mb 1 in Physics

2007-11-10 00:57:33 · 4 answers · asked by Anonymous in Mathematics

1) given the following data:
2C (s) + O2 (g) ---> 2CO (g) delta H = - 222 kJ mol -1
2CO (g) + O2 (g) ----> 2CO2(g) delta H = -566 kJ mol -1
what is the standard enthalpy f combustion of carbon?

2)the standard enthalpy changes for the combustion of decane, octane and ethene are - 6778, -5470, -1411 kJ mol -1. use these data to calculate the standard enthalpy change for the cracking of decane :
C10H22(l) ----> C8H18 (l) + C2H4 (g)

2007-11-10 00:49:11 · 1 answers · asked by Anonymous in Chemistry

Calculate the standard enthalpy of formation of magnesium carbonate, using the following information. the standard enthalpy of combustion of magnesium is - 602 kJ mol -1 and that of carbon is - 394 kJ mol -1. the standard enthalpy change for the decomposition of magnesium carbonate in the reaction:
MgCO3 (s) ----> MgO (s) + CO2 (g)
is 100 kJ mol-1

2007-11-10 00:48:21 · 1 answers · asked by Anonymous in Chemistry

2007-11-10 00:26:31 · 1 answers · asked by Anne R 1 in Astronomy & Space

whay are the purposes of research?

2007-11-10 00:23:57 · 3 answers · asked by sheshe 1 in Chemistry

2007-11-10 00:22:48 · 6 answers · asked by Anonymous in Astronomy & Space

2007-11-10 00:12:32 · 14 answers · asked by daphne 2 in Mathematics

2007-11-10 00:06:01 · 4 answers · asked by Jill 2 in Physics

Triangle ABC is right-angled at B. D and N and points on AC and AB respectively such that DN is parallel to BC. Draw DM perpendicular to BC. Prove that:

DM² = (DN)*(MC)
DN² = (AN)*(DM)

2007-11-10 00:03:36 · 3 answers · asked by Akilesh - Internet Undertaker 7 in Mathematics

while calculating the equilibrium constant for the reaction between hydrogen and iodine, how can we just assume that the concentrations of hydrogen and iodine at equilibrium are equal? does the initial concentration of hydrogen and iodine have to be equal in order for this to be true or are their eqm, concentrations equal in every case?

2007-11-10 00:00:11 · 2 answers · asked by amandac 3 in Chemistry