I was thinking, why is it that a planes reaches a top speed, what is the limiting factor?
It comes down to drag from air resistance, when the thrust force and the drag force are equal and opposite, the plane must stop accelerating; therefore, it has reached its top speed.
But does the thrust force the plane is capable of decrease with speed? I know this must vary depending on the prop, but in general.
If the maximum thrust force does in fact decreas with speed, I picture it like this. If you plotted thrust versus speed, you would end up with a line that starts high (speed 0) and it would slowly decrease to some number (at high speed) maybe even theortically hitting 0.
Now plot the drag force with speed and I picture the force starting at 0 (speed 0) and increasing with speed, theoretically this could reach infinity.
So no if you were to plot both the thrust vs speed and the drag vs speed on the same graph, the point where the lines intersected would be the maximum speed achievable in level flight.
Is this correct, can any enlighten me?
Does the amount of thrust possible decrease with the speed of the plane? (not talking about rpm or engine related, I mean linear motion of the plane)
p.s. Obviously I didnt consider altitude air density fluctuations, but if you are in level flight (constant altitude) they would not have an affect.