Iron ore, solid carbon, and limestone are warmed to very high temperatures in an oven during the process of extracting pure iron. Afterwards, the oven contains pure iron and a waste product called sl*g. The total mass of the iron and sl*g is less than the total mass of the iron ore, solid carbon, and limestone. What happened to the remaining mass?

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?