The first one is electrical energy
Answer:
The contribution of the wavelets lying on the back of the wave front is zero because of something known as the Obliquity Factor. It is assumed that the amplitude of the secondary wavelets is not independent of the direction of propagation, Sources: byju's.com
Answer:
0.686 g of ice melts each second.
Solution:
As per the question:
Cross-sectional Area of the Copper Rod, A = 
Length of the rod, L = 19.6 cm = 0.196 m
Thermal conductivity of Copper, K = 
Conduction of heat from the rod per second is given by:

where
= temperature difference between the two ends of the rod.
Thus

Now,
To calculate the mass, M of the ice melted per sec:

where
= Latent heat of fusion of water = 333 kJ/kg

The first one is: head
Second one is: 10 trillion km