The answer is to u question is: C
Answer:
24.3KW
Explanation:
A)The kinetic energy is changing, the potential energy is changing and the chemical energy in form of fuel powering the engine also is changing
The kinetic energy is increasing as the body gain speed, the potential energy also increases as the body gain height against gravity and the chemical energy in form of fuel decreases as the body burn the fuel to create a lifting force
B) The workdone by the lifting force = the change in kinetic energy + the change in potential energy
C)The time taken in seconds to do the work is the variable needed
D) average power generated by the lifting force = (change in kinetic energy + change in potential energy) / time taken in seconds
Average power = 1/2 * m(mass) (Vf-Vi)^2 + mg(hf-hi) /t where vf is final speed and vi is initial speed at rest = 0, similarly, hf = final height and hi = initial height.
Average power = 1/2*810*7^2 + 810*9.81*8.2/3.5s
Average power = (19845+65158.02)/3.5 = 24286.577 approx 24.3kW
