a piece of aluminum has density 2700 kg/m3 and mass .475 kgthe aluminum is submerged in a container of oil density 850 kg/m^3a spring balance is attached with the string to the piece of aluminumwhat mass reading will the balance register in kg for the submerged metal
There's nothing wrong with schrader valvesAnd what's messed up with your tubes? A few patches aren't a problem Tires generally go flat on their own - that's normalFor a 27 tire, you'll usually have to pump them up every week or so(For 700x20c tires, you have to pump them up every day.) If you have to pump up more than that, look for a hole and patch it or replace the tubeAs for which tube to use, it needs to be 27 - but beyond that, you have some latitudeIt's a very common size, so you should be able to find tubes at Wal-Mart or Target with no problem Just make sure that 1 1/4 is one of the sizes that the tube you pick is rated forOf course, your bike shop has appropriate tubes as wellAround here, they're usually about $4 eachBrands don't really matter - they're all pretty much the same (except for tubes like the Slime tubes, of course.) Personally, for my bikes with lower tire pressures (tend to be fat tires, like 27x1 3/4 or so) I prefer the `Slime' tubes, as if they do get a flat they'll often fix themselvesBut don't get Slime tires if the tire has over 60 lbs of pressure - it'll just make a sticky mess if you get a flatSlime doesn't really work at pressures higher than thatSlime tubes cost around $7 each here, but if your tire pressure is lower, they're so worth it in not having so many flats(I've also found that puncture resistant tires are so very worth it, but that's another matter.)
the volume of the aluminum in question is 0.475/2700 1.76 x 10^-4 cubic metersthe mass of the oil displaced when the aluminum is submerged is 1.76 x10^-4 850 0.1496 kg 0.475 kg - 0.1496 kg 0.3254 kg 325.4 grams I did some rounding so you may wish to run the number yourself.
