text: ok, i need some serous science fair help!? my science fair question is : how  do salt, sugar, and vegetable oil affect how fast water boils? so, i took the water (bowl a and added salt to it) and watched the thermometer and took time until it boiled. then i did the same with the sugar and the vegetable oil. and i made a graph of the time vs. ingredient (salt, sugar and oil) but my science teacher said i need to measure the density. i know that density is mass and volume divided. mass is how much it weighs with the water and the ingredient, but i would need an accurate scaled for that, and i don't have one. i used a cup for my measurement of the water and a tablespoon for the ingredient. and, i know that volume is the space it takes up. so, could someone who really can help me measure the density for me. i'll give u the time also. salt: 5 min. 8 sec sugar:  3 min. 46 sec vegetable oil: 4 min. 17 sec  i know that many of u will play around and not be able to help me but for those of u who can, thank you! an easier way is to approximately calculate the density rather than trying to measure it.  abbrivations used: cc = cubic centimeter ml = milli-liter g = gram  you used one cup of water and a tablespoon of the additive.  1 u.s. tablespoon = 0.5 u.s. fl. oz. (14.8 ml, 14.8 cc) 1 u.s. cup = 8.0 fl oz (u.s. fluid ounces) (237 ml, 237 cc)  water density = 1.000 g/cc, liquid [from: http://en.wikipedia.org/wiki/water]  vegetable oil calculation: liquid vegetable oil density = 0.93 g/cc [from: http://www.mcelwee.net/html/densities_of_various_materials.html]  to get the combined density of oil and water, multiply each volume by the density of each substance and divided by the total volume:  density: ((0.93 g/cc * 14.8 cc) + (1.000 g/cc * 237 cc)) / (14.8 + 237 cc) =  (13.764 g + 237 g) / 251.8 cc = 0.995 g/cc [for vegetable oil and water]  salt & water calculation: nacl (table salt) density = 2.16 g/cc, solid [from: http://en.wikipedia.org/wiki/nacl]  you added 14.8 ml of salt to the water (237 ml) for a total volume of 251.8 ml (251.8 cc)  to get the combined density of salt and water, multiply each volume by the density of each substance and divided by the total volume:  density: = ((2.16 g/cc * 14.8 cc)  + (1.000 g/cc * 237 cc)) / 251.8 cc = (31.968 g + 237 g) / 251.8 cc = 1.068 g/cc [for salt and water together]  sugar and water calculation: sugar (sucrose) density = 1.587 g/cc, solid [from: http://en.wikipedia.org/wiki/sucrose]  you added 14.8 ml of sugar to the water (237 ml) for a total volume of 251.8 ml (251.8 cc)  to get the combined density of sugar and water, multiply each volume by the density of each substance and divided by the total volume:  density: = ((1.587 g/cc * 14.8 cc)  + (1.000 g/cc * 237 cc)) / 251.8 cc = (23.488 g + 237 g) / 251.8 cc = ( 260.488 g) / 251.8 cc =  1.0345 g/cc [for sugar and water together]  hope this helps!