Well said xerves the trolley won't take off, same answer as before the wheels will turn provided I hold the trolley steady, if I push the trolley the wheels will be turning faster than the belt.
Physics Puzzle
- Thread starter Softus
- Start date
Well said xerves the trolley won't take off, same answer as before the wheels will turn provided I hold the trolley steady, if I push the trolley the wheels will be turning faster than the belt.
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The OP doesn't say the conveyor speed matches the speed of the aircraft, it says it matches the speed of the wheels.
Wrong, because the conveyor speeds up to match the wheels. The plane will still be moved along the belt though.
Let's use an analogy:
You know those travelator things that they have at airports? Those moving walkways? OK, you are wearing roller skates and standing on one.
Both the floor and the handrail are moving at 10mph in a forward direction so your roller skate wheels aren't moving. Now something goes wrong with the handrail and it stops (though the floor keeps moving). So now you are stationary (hanging on to the handrail) and the conveyor (floor) is moving at 10 mph. Your wheels are now moving at 10 mph. Someone now switches the handrail back on but gets it running in the wrong direction. You are now hanging onto the handrail and travelling backwards at 10 mph. The conveyor (floor) is travelling forward at 10 mph. Your wheels are now travelling at 20 mph.
Now substitute the floor for the conveyor and the thrust from the engines for the handrail. You will now reach take off speed with your wheels turning at twice the speed. Gedditt yet? (he won't).
Try it with the trolley, You're standing on the end of the travelator and the trolley is on the belt, the wheels are turning at the speed of the belt coming towards you, to get the trolley to move forward you have to push it so the wheels are turning faster than the belt.
However many times you argue the point the wheels have to turn faster or there is not forward travel. Geddit yet (he won't)
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Of course the trolley won't take off(!)
But the fact that you can hold it stationary against the movement of the belt is all the proof you need that the answer to the original question is that the plane will take off.
You will need to pick a trolley without stuck wheels.
But the fact that you can hold it stationary against the movement of the belt is all the proof you need that the answer to the original question is that the plane will take off.
You will need to pick a trolley without stuck wheels.
Wrong again, you would simply have to hold the trolley while walking in the opposite direction at the side of the belt. The trolley would be moved forward along the belt.
All the time the speed of the wheels and the convetor are equal how can the plane move alone the belt. it doesn't matter how fast the wheels are turning, if the belt is going at the same speed.
Doitall wrote
How much faster ?.
Any conveyor system has drag/friction to overcome.
The fact is you don't know how much this is in either case.
How much faster is irrelevant, the OP says they will be the same
Diyitall wrote
They can never be equal.
Rocket propelled thrust is one way.
If it was a person standing on the belt then a good boot up the ar@se would be another way.
Correct. The wheel rpm is totally irrelevant.
They can never be equal.
Rocket propelled thrust is one way.
If it was a person standing on the belt then a good boot up the ar@se would be another way.
Correct. The wheel rpm is totally irrelevant.
Incorrect. The belt cannot travel at the same speed as the wheels.
Doitall wrote
How much faster ?.
Any conveyor system has drag/friction to overcome.
The fact is you don't know how much this is in either case.
How much faster is irrelevant, the OP says they will be the same
Its totally relevant.
You have lost sight of what the OP said.
I've got to admit I've no answer to that one. I think I'm beginning to agree with you.
So the only effect the thrust would have would be to increase the speed of the conveyor in the opposite direction? My head is starting to hurt now.
I've got to admit I've no answer to that one. I think I'm beginning to agree with you.
Its easy.
For starters the rpm of the wheels can never match the rpm of the conveyor.
If you consider this to be incorrect then define speed and how it is measured in relation to the movement of the conveyor and the movement of the wheels.
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