Remember the definition of work done.
Work done is force(F) times displacement(x)
∴ W = F.Δx
According to Newton's 2nd law of motion,
F = ma
∴ W = ma.Δx ---- (i)
Using the kinematical equation v²-u² = 2ax,
aΔx = (v²-u²)/2
Plug this value in (i),
∴W = m[

]
∴W =

Which is nothing but change in kinetic energy.
That is how kinetic energy is derived
Answer:
A. The brakes used a coil system to convert the kinetic energy into potential energy stored in the brakes
Explanation:
Based on the law of conservation of energy, the brakes used a coil system to convert the kinetic energy into potential energy stored in the brakes.
The law of conservation of energy states that energy is neither created nor destroyed in a system but it is transformed from one form to another.
As the airplane slows down, the kinetic energy which is presented in the motion of the plane is gradually converted to potential energy.
The potential energy is the energy due to the position of a body.
Answer:
Positive velocity and negative acceleration
Explanation:
An object moving in the positive direction has a positive velocity.
An object that's slowing down while moving in the positive direction has a negative acceleration.

Actually Welcome to the concept of resistors,
The equivalent circuit is given as,
1/Rp = 1/3 + 1/6 + 1/9
1/Rp = 6+3+2/18
1/Rp = 11/18
Rp = 18/11 ==> 1.63 ==> 1.6 ohms
hence the equivalent resistance of the circuit is 1.6 ohms