How many turns of the crank are needed to raise the temperature of the drum by the amount specified above?

Data:

Diameter of drum = 7.6 cm
Mass of drum: 209 g
Specific heat capacity of drum: 0.315 cal/(g°C)
Change in temperature of the drum: 7.8 °C
Mass of the hanging mass: 5.00 kg

Equations I have:

ΔH(in calories) = [0.215MD]ΔT
|ΔW | = 4.18ΔH
Friction Work = −(mg)(ncD) (where cD is the circumference of the drum = 23.9 cm and n= number of cranks)

I have tried over a dozen times and I'm not sure what I have been doing wrong. Any help would be appreciated!!

Question

How many turns of the crank are needed to raise the temperature of the drum by the amount specified above?

Data:

Diameter of drum = 7.6 cm 
Mass of drum: 209 g 
Specific heat capacity of drum: 0.315 cal/(g°C) 
Change in temperature of the drum: 7.8 °C 
Mass of the hanging mass: 5.00 kg 

Equations I have:

ΔH(in calories) = [0.215MD]ΔT
|ΔW | = 4.18ΔH
Friction Work = −(mg)(ncD) (where cD is the circumference of the drum = 23.9 cm and n= number of cranks)

I have tried over a dozen times and I'm not sure what I have been doing wrong. Any help would be appreciated!!