Answer:
The force per unit length is 
Explanation:
The current carrying by each wires = 2.85 A
The current in both wires flows in same direction.
The gap between the wires = 6.10 cm
Now we will use the below expression for the force per unit length. Moreover, before using the below formula we have to change the unit centimetre into meter. So, we just divide the centimetre with 100.

It's still 20 kg. Mass doesn't change according to gravity, only weight changes.
Answer:
The transfer of heat by the movement of fluid is called Convection Heat Transfer
Explanation:
Heat transfer by convection is the transfer of heat by fluid transport from one place to another, such that convection takes place when the heat that comes in contact of fluid containing body is moved to other parts of the container by the transporting fluid
Heat is transferred within a fluid medium mainly by convection (movement of heat by the transfer of fluid particles in the medium)
Convection heat transfer is a combination of conduction and advection heat transfer