A) lighting an electric lamp as it becomes darker
(a) Let's convert the final speed of the car in m/s:

The kinetic energy of the car at t=19 s is

(b) The average power delivered by the engine of the car during the 19 s is equal to the work done by the engine divided by the time interval:

But the work done is equal to the increase in kinetic energy of the car, and since its initial kinetic energy is zero (because the car starts from rest), this translates into

(c) The instantaneous power is given by

where F is the force exerted by the engine, equal to F=ma.
So we need to find the acceleration first:

And the problem says this acceleration is constant during the motion, so now we can calculate the instantaneous power at t=19 s:
False, we lack cell walls whereas they have cell walls.
1. HP is the output horsepower rating of an engine, while Brake horse power is the input brake horsepower of an engine. ... Brake horse power is the measurement of an engine's power without any power losses, while HP is less the power losses Brake horse power