Quenching lead shot in a bath. lead shot having an average diameter of 5.1 mm is at an initial temperature of 204.4°c. to quench the shot, it is added to a quenching oil bath held at 32.2°c and falls to the bottom. the time of fall is 15 s. assuming an average convection coefficient of h = 199 w/m².k, what will be the temperature of the shot after the fall? for lead, p = 11 370 kg/m and cp = 0.138 kj/kg . k.

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)