Low-5.0 said:JT, The bike tires and treadmill are both spinning at 30mph any you're standing beside the bike(on solid ground) holding it statioinary. You take a step forward, pushing the bike with you. The tires and treadmill increased to 31mph. How did they increase spead? You moved the bike forward. You only took one step so the bike is stationary again, with it's wheels spinning at 31mph now, but you had to move forward to get that increase in spead. If you pushed the wheel's themselves, then yes the treadmill would compensate for that and there would be no forward motion.
GRGT1994 said:Who cares how it moves? There could be a million monkeys turning small cranks. Whatever. There still is no breaking force exerted on the plane. Engines fire, the plane moves forward.
parchisi said:The tires and treadmill are going at 30 mph, and you push the bike forward at 1mph, so then the wheels are going 31mph. You then say that the treadmill speed increases to match the 31mph, but when you increase the speed of the treadmill 1mph, that in turn also increases the speed of the wheel by 1mph, so that the wheel is now turning at 32mph and the treadmill is goign at 31mph. It is impossible to make up that 1mph difference in speeds, and the question specifically says that the speed of the wheel and the speed of the treadmill must remain the same.
Stangster5.0 said:The conveyor belt spins in reverse the exact same speed as the wheels at any given time.
Swarzkopf said:Nothing can move faster than the speed of light. Light travels only at the speed of light and cannot move faster.
Okay, lets say a guy in outerspace points two flashlights at opposite ends of the universe and turns them on. The light beams are shining away from each other.
Relative to one another, are the light beams moving faster than the speed of light? They can't be, because nothing can move faster than the speed of light, right? Discuss.
so what your a pilot what do you know94GTPilot said:Ok... Now for anybody that doesn't know me, I am a pilot myself, and finishing up my BS in Aviation Operations, so let me give you all a little insight into the world of flight, as it pertains to this problem....
I completely agree with Low-5.0, mo_dingo, and the others that have a grasp on this concept. What people need to realize is that an aircraft uses a propeller or engine nozzle to transfer the work done by the engine to the air to propel you forward. In contrast, your car uses tires to transfer the work done by your engine to the ground to propel you forward. HUGE difference, and it doesn't matter what anyone says about the conveyer belt matching the speed of the tire because IT IS IRRELEVANT TO AIRCRAFT PROPULSION. The belt could spin the tires backward at 50,000 rpm, but what matters is how the plane moves through the air. The propeller cuts through the air, providing a forward thrust that, unless is completely counteracted, WILL pull the plane forward.
I think where people are getting hung up is that the aircraft uses its wheels to move it forward, or that there is some relationship between how fast the ground is moving/rotation of the tires to the airplane itself. You guys that used the treadmill analogy had it perfect, so let me add to it. Instead of having someone next to the bike, pushing it forward, attach a winch infront of the treadmill, with the cable fixed to the front of the bike. Now it doesn't make a difference if the treadmill and tires are spinning at 10 rpm or 10,000 rpm, as long as it is not going anywhere. Now are there people out there that think that by retracting the cable into the winch, and therefore pulling the bike forward (much like a propeller or jet engine would do in the case of aviation) that the bike would still not move forward???
In conclusion, propulsion in aviation has absolutely no bearing on what the ground is doing... AIR IS THE MEDIUM for flight, GROUND IS THE MEDIUM for driving... Any questions??
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?