July 21, 2013

## How to calculate the percentage of gold (by mass) in the mixture?

You have a piece of gold weighing 9.36g. Its volumes is .657 cm^3 Assume that the metal is an mixture of gold and silver. which have densities of 19.3 g/cm^3 and 10.5 cm^3, respectively. Assume that there is no change in volume when the pure metals are mixed.

Let g stands for gold and s stands for silver. Therefore
g+s =9.36……………….i
v1 and v2 are their volumes and d1 and d2 are their densities
v1 +v2= 0.657…………ii
v1d1+v2 d2=9.36
19.3v1 +10.5v2=9.36…..iii
Multiply ii by 19.3 and solve with iii
19.3v1 +19.3v2 =12.6801……..iv
subtract iii from iv
8.8v2=3.3201
v2 =0.37728409…………..v
Using ii and v
v1=0.27971591…………..vi
g=v1xd1=0.27971591×19.3=5.398517063gm…………vii
s =0.37728409×10.5=3.961482945 gm………………….viii
Therefore gold is ={5.398517063/9.36}x100=57.676%

## How to work out percentage backwards?

Example : A car has had a value increase of 20% from last year. If the price is currently £20,000 what was the price last year?

20000/120(%)x100(%)=16667

## What is the best Compact Camera available at the moment ?

What is the best Compact Camera available at the moment ? Money not an issue just the best that you can get or will be out in the next few months
Sony Nex 5 as the benchmark or Sony Tx100V 16mp

thanks

Fuji X100 (if you’ve got about £1000 burning a hole in your pocket)

http://www.whatdigitalcamera.com/equipment/reviews/compactcameras/128880/1/fujifilm-finepix-x100-review.html

Fuji F550EXR if you’ve only got about £240 – £300 to spend

http://www.fujifilm.com/products/digital_cameras/f/finepix_f550exr/

## where can i get a old fashioned digital camera?

i want a camera that looks like the Canonet 28 serious 35mm rangefinder, but it needs to be digital because film costs to much.

Kim, the Fuji x100 is meets what you are describing but check it out:

Why do you care what your camera looks like? Why would you want a camera that looks like something that it is not? Do you enjoy being deceitful?

The Canonet 28 is a fine camera and has a lot more to offer than simply what it looks like.

Yes, film can be costly but learning to use it well instills discipline, as well does effectively learning to shoot on a rangefinder camera. In some cases film can look nicer than digital too. And if you’re worried about cost, consider the fact that the Canonet 28 was made in the late 1960′s and is still working, whereas the Fuji X100 will be either dead or obsolete in 10 years or less. Value and cost are funny words. Film may cost more money, digital costs you in simply not having a the authentic film experience.

Instead of just being cosmetic, how about giving the thing that you’re naturally attracted to a serious try?

Good luck, whatever decision you make!

## Find the slope of an inclination of 37 degrees?

I have a project on The Olympic Ski Jump in Lake Placid. I haven’t learned how to determine slope from degrees yet, please help?
How do you express it as a fraction?