What do these two changes have in common? Erosion caused by wind
Snowflakes forming in a cloud
Both are only physical change
Both are chemical change
Both are caused by heating
Both are caused by cooling

yes the answer is total mass in unchanged   : )

the correct answer is c

35. a insulated cylinder of solid gold (k 310 kw/m-k) of radius v2 m and height 5 m is heated at one end until the temperature at each point in the cylinder is given by w(r, y, z) (30 z2)(2-(r2+ y2). determine the rate of heat flow across each horizontal disk given by z 1, z 2, and z 3, identifying which has the greatest rate of heat flow across it.

explanation: