how much energy would it take to completely melt 200kg of lead if the lead is currently at 25 degrees celcius
q1 = heat required to move T from 25 to melting point of Pb. You will need to look up the melting point value.
q1 = mass Pb x specific heat Pb x (Tfinal-Tinitial).
q2 = heat to melt solid lead at the melting pont to liquid at the melting point.
q2 = mass Pb x heat fusion.
Total q = q1 + q2