Does anyone know how to do this please

See the answer below.

Explanation:

The latent heat of fusion is defined as the amount of energy needed to make a phase change from solid to liquid. And it can be calculated by means of the following expression:

where:

Qfusion = Heat Energy [J]

m = mass = 0.65 [kg]

Dh =  latent heat fusion = 330000[J/kg]

2)

We know that energy can be calculated from power, where power is defined as the relationship between energy over time.

where:

P = power = 60 [w]

E = energy [J]

t = time = 5 [min] = 300 [s]

The mass change due to the process is equal to:

Now using the following equation for the latent heat of Fusion, we can calculate this value: