1.A uniform ladder with a mass of 15 kg is placed on a frictionless vertical wall. An 80 kg person climbs up the ladder. If the coefficient of friction between the floor and the base of the ladder is 0.15, how far did the person climb?
2.The dissolved oxygen of sample water is 1.5 mg/L. At 25 C, the dissolved oxygen of the dilution water is 8.25 mg/L. You are told the BOD5 of the sample is 130 mg/L. You have a target final dissolved oxygen of 3.0 mg/L (give yourself some leeway). What should the sample volume be?
3.Modify function random0 so that it can accept 0, 1, or 2 calling arguments. If it has no calling arguments, it should return a single random value. If it has 1 or 2 calling arguments, it should behave as it currently does.