I'm trying to figure out the answer but i'm getting nowhere. me understand how to calculate it.

You don't need to pay attention to the area in this case. We are trying to figure out the mass. What do we need? F= m*a (Force= mass * acceleration of gravity). acceleration of gravity on earth: 9.81m/s^2. so 15000= m*9.81. We need m (Mass) so m= 15000N/ 9.81m/s^2 = 1529.051988 ≈ 1529.05kg.
the mass of the empty plane is therefore 1529.05kg

b) to produce electrical charges;

Explanation:

Electrical generators are used in a circuit to produce electrical charges. The flow of these charges actually produces electrical energy in a circuit which is needed and essential to power devices and gadgets.

A generator uses mechanical energy through the movement of its parts to produce electrical energy. The flow of electrons streams produces the electrical energy which helps to produce power.

A generator works on the basis of electromagnetic induction using the movement of electric charges.