The answer is two (4 -3)
Zero is not a SF
Its to capture light or to focus. don't forget to like. :D
well in my own words, i'd saw the the doppler effect is similar to light because sound has a speed, and light does too.
so my theory is if you go fast enough everything would just become black, or maybe white? idk its hard to explain
but what my point is, is taht the doppler effect works in the same way, like if a car is moving towards you the sound is being emitted from the car and being pushed by the speed of the car making it have a much higher pitch, when the car is going away however it drops to a lower pitch due the the sound waves being DRAGGED by the car.
there hoped this helped I guess
Work done by the force = Force x displacement. Power = work done/time = F.s/t = F.u.t/t = F.u = 95 x 20 = 1900J. {S=ut because acceleration is zero since car is moving at constant velocity}.
