Cam you blind a video camera with a fire extinguisher ?
To expand on 1B. When you have a counting number, the number of sig figs is determined by the context in which the number is used. If you say: 1. About 25000 people were there, it would be 2 sig figs. 2. 25000 votes were cast, it could be 2,3,4,5, depending on how good that statement was. It could be +/-1 or +/-10 votes or +/-100. Notice during elections when they do a recount, they never get the same exact answer. 3. Henry counted out 25000 pennies in front of ten witnesses, it would be infinite because it was an exact count. Some people use the decimal point system of 25000. to indicate this would be 5 sig figs or an infinite number where 25000 without the dot would mean 2 sig figs. Bottom line, for these types do what your teacher wants on the test. I teach it would be undetermined without the context.
Check out Tank fittings with a plumbers merchant. Half inch tank fittings are available in brass. There are also Flat brass back nuts for sink Taps, also in half inch size.
