Faster or Slower?

Discussion in 'Physics & Math' started by Motor Daddy, Apr 25, 2022.

  1. Motor Daddy Valued Senior Member

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    At 14:45 the object is placed on the treadmill.

    If the object would advance towards the front of the treadmill (towards controls) would it be moving faster or slower than the treadmill belt?

    I claim that in order to move faster than the treadmill belt the craft would have to beat the belt to the rear, falling off the treadmill BEFORE a line on the belt would get there.

    What say you?
     
    Last edited by a moderator: Apr 25, 2022
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  3. origin Heading towards oblivion Valued Senior Member

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    Faster than the belt, but in the opposite direction.
     
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  5. Motor Daddy Valued Senior Member

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    So let's just say there was a line on the belt at the midpoint and the craft is placed on the belt on the line when the line is at the midpoint.

    Let's just say the line takes .1 second to go from midpoint to the end where it "falls off" the rear end.

    So you're saying that if the craft is placed on the belt at the midpoint on the line, that the craft will take less than .1 second to reach the front end of the belt?

    If the belt travels at 2 ft per .1 second from midpoint to end, you're saying the craft will travel forward FASTER than the belt in the forward direction, traveling 2 ft to the front in LESS THAN .1 seconds? That the craft will reach the front before the line reaches the rear?

    "Faster than the belt" (regardless of direction) means traveling the same distance in less time, or a greater distance in the same time.

    There is NO WAY the craft is faster than the belt. The craft barely moves forward while the belt whips around traveling much more distance per time than the craft does.
     
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  7. exchemist Valued Senior Member

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  8. billvon Valued Senior Member

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    It's a simple matter of available power. As long as you have two mediums moving at different speeds (say, wind vs belt, or wind vs water) you can get power out of the difference. In this case, as long as the air is moving at a different speed than the belt, you can get power out of it. How much power, and how fast you can go, is determined by the efficiency of the design.
     
  9. Motor Daddy Valued Senior Member

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    The question is not about power, the question is about being FASTER or SLOWER than the belt.

    Speed is distance and time.

    So to say the craft is FASTER than the belt means it either travels more distance in the same time, or the same distance in less time.

    It has nothing to do with power. It is distance and time.
     
  10. origin Heading towards oblivion Valued Senior Member

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    No. Let's say the craft is going the same speed as the belt, then it would not move forward or backward, just like a runner on a tread mill. If the craft was going 1 foot per minute faster than the belt it would move forward at 1 foot per minute.
     
  11. Motor Daddy Valued Senior Member

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    According to your logic, If I stand there and watch the belt travel past me, and I don't change position, then I am moving the same speed as the belt. Outrageous!

    The speed of the belt is say 2ft/.1 sec. compared to the frame of the treadmill.
    The craft's speed compared to the frame of the treadmill needs to be FASTER THAN 2ft/.1sec in order to be faster than the belt.

    How could you possibly claim that an object ON THE BELT, traveling with the belt, is traveling the same speed as the belt when you are claiming that a craft that was placed midpoint of the treadmill, that maintained that position while the belt moved, that would be the same speed as the belt?

    So you're saying the craft would be traveling the same speed as the belt if it didn't move forward or backward, AND the craft riding the belt would be traveling the same speed???

    You can't have your cake and eat it too!
     
  12. billvon Valued Senior Member

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    Nope. It is about being a different speed than the belt. Thus it can be faster or slower; it just can't be the same speed if you want power.
    Right. That's the definition of velocity, so yes.
    You are getting your frames mixed up.

    If the craft is on the belt, and its wheels are turning so that it is traveling the same speed as the belt - but in the opposite direction - then to an observer next to the treadmill, it is not moving.
    If the craft is on the belt, and its wheels are turning so that it is traveling the same speed as the belt - but in the opposite direction - then to an observer on the belt itself, it is moving at the same speed the whole room seems to be moving.
     
  13. Motor Daddy Valued Senior Member

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    The power can be measured at the outlet. Without the craft on the belt the power is less than with the craft on the belt.

    You are trying to claim free energy. You are claiming the treadmill can power the craft for free.

    The treadmill draws a higher amperage with the craft on the belt. That is a FACT!

    The treadmill is POWERING the craft, and it can be measured in more amps!
     
  14. Motor Daddy Valued Senior Member

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    You measure the speed of the belt compared to the frame of the treadmill, not the craft.
    You measure the speed of the craft compared to the frame of the treadmill, not the belt.

    You compare the two speeds and determine which is FASTER, the belt or the craft. Faster meaning which travels more ft/sec compared to the frame of the treadmill.
     
  15. origin Heading towards oblivion Valued Senior Member

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    Oh for crying out loud stop trolling! I didn't say or imply anything like that. You haven't changed your trolling ways.
     
  16. origin Heading towards oblivion Valued Senior Member

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    Your purposely misrepresenting what I said just to argue and troll. Don't want to play, bye.
     
  17. billvon Valued Senior Member

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    OK. Then that's easy. The speed of the craft will always be the same as or faster than the speed of the treadmill frame. (It also might change direction.)
    Nope. The craft extracts power from both the treadmill and the air.
    No one has claimed that, other than you.
     
  18. Motor Daddy Valued Senior Member

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    You are stating which is faster compared to the frame, the belt or the craft.

    You are not comparing which is faster, the craft or the frame.

    You are measuring the speed of the craft against the frame.
    You are measuring the speed of the belt against the frame.
    You are stating which is faster, the belt or the craft.

    It is like measuring 2 football player's speed on a football field.
    You measure one player's speed to be 50 yards of field in 7 seconds.
    You measure the other player's speed to be 50 yards of field in 6 seconds.
    You compare the two speeds to find out which player is faster measured against the field.

    In this case the "field" is the frame.
    One player is the craft.
    The other player is the belt.
    Which one is faster??

    The craft does not extract power from the air. The power is all from the wall outlet. Unplug the treadmill and the motion will come to a halt. All of it, the belt and the craft.
    The outlet is powering the entire show. 120 volts and say 10 amps without the craft on the belt (1,200 Watts of power) and 120 volts and 11 amps with the craft on the belt, 1,320 Watts of power. (exaggerated amperage to make my point)
    The craft is consuming 120 Watts of power.

    So you deny the outlet is powering the craft?? Free energy??
     
    Last edited by a moderator: May 2, 2022
  19. billvon Valued Senior Member

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    Incorrect. If there were no air, the craft would stick with the belt and not move relative to it.
    And if there was no air, the craft would come to a halt relative to the belt.
    Nope. Again it is the difference in speeds. Some power comes from the treadmill; some comes from the air.

    For proof of this, consider the test done on the desert. There was no outlet that the desert was plugged into. There was just the stationary ground and the moving wind. If there was no wind, the vehicle would just sit there, going whatever speed the ground was. If there was no ground, the vehicle would move at wind speed. However, since there is a difference, the vehicle is able to use that difference to generate power and move faster than both the ground and the wind.
     
  20. James R Just this guy, you know? Staff Member

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    Indeed. It's been 10 years. Under ordinary circumstances, I imagine that should be long enough to start to grasp the concept of a reference frame - especially when it has been carefully explained.

    So let's clear up Ghost's confusion.

    We have a moving conveyer belt and a wheeled vehicle rolling along on the belt.

    Consider the view of a person standing on the ground next to the conveyer belt. Call the direction to that person's right the positive x direction, and the direction to the left the negative x direction. Say that the belt is moving with speed v_belt to the left, from that person's point of view. Then its velocity is -v_belt (with a minus sign to show that it's moving to the left). The person standing next to the belt sees the vehicle moving with a velocity of v_vehicle. Notice, I have not specified whether it is moving left or right, so v_vehicle could be positive or negative.

    Next, consider the view of a person whose feet are glued to the conveyer belt. From that person's point of view, the speed of the belt is zero: it does not move relative to the person that is glued to it. Let the velocity of the vehicle, relative to this observer, be u, which could be positive or negative, depending on whether the vehicle is moving to the left or right according the person who is glued to the belt. The plus sign tells us that it moving to the right, according to the person who is glued to the conveyer belt.

    The three velocities defined above are related by the following equation:

    v_vehicle = +u - v_belt.

    Let us now consider a few specific cases of these general equation.

    Case 1: u=0

    This is the case where the vehicle's speed relative to the observer on the belt is zero. That is, the vehicle remains at all times at a constant distance from the person who is glued to the belt. According to that person, the vehicle is stationary, hence u=0. Our equation above immediately gives us:

    v_vehicle = 0 - v_belt = -v_belt.

    This result tells us that the person on the ground, standing next to the belt, will see the vehicle moving to the left with the same speed as the belt, which makes perfect sense.

    Case 2: u=+v_belt

    This is the case where the glued observer sees the vehicle moving to the right along the belt, with a speed that happens to be equal to the belt's speed as measured by the person standing next to the belt. Our general equation gives:

    v_vehicle = +v_belt - v_belt = 0

    That is, the person on the ground sees that the vehicle is stationary relative to the ground. The distance between the observer standing next to the belt and the vehicle remains constant at all times. That observer sees the belt moving to the left and the vehicle's wheels trying to roll it along the belt to the right. The net effect is that the belt's leftward motion cancels out the vehicle's attempts to move towards the right, and the result is that the vehicle does not move at all relative to the ground observer.

    Case 3: u>+v_belt

    Our equation tells us that in this case v_vehicle > 0, which means the vehicle is moving to the right relative to the ground. This is the case where the vehicle is being "driven" rightwards along the belt faster than the belt is moving leftwards, from the point of view of the ground observer.

    Case 4: 0<u<+v_belt

    Our equation tells us that v_vehicle < 0, which means the vehicles moves leftwards relative to the ground. This is the case where the vehicle is "trying" to drive towards the right, but the belt is moving so fast to the left (relative to the ground) that the vehicle nevertheless ends up moving to the left (relative to the ground).

    Case 5: u<0

    Our equation tells us that v_vehicle < -v_belt. This is the case where the person who is stuck to the belt sees the vehicle driving leftwards along the belt. The person on the ground next to the belt sees the vehicle moving to the left at a greater speed, because not only is it "trying" to drive leftwards along the belt, but the belt is also carrying it along to the left.

    ---
    I think that covers all of the possibilities for the case of the belt moving to the left.
     
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  21. exchemist Valued Senior Member

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    Indeed. It's all about reference frames. I simply don't believe Motor Daddy is so thick he doesn't get that. This is most likely another of his exercises in trolling - for which he has considerable form.

    Please Register or Log in to view the hidden image!

     
  22. Motor Daddy Valued Senior Member

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    You don't even know the difference between speed and power.

    If there were no air there could still be relative motion to the belt, as inertia is proportional to acceleration. So place the craft on a moving belt and the inertia of the craft will cause the craft to move at a different speed than the belt, until the craft finally travels at the same speed as the belt. So an object on the belt, traveling with the belt at the same speed is traveling THE SAME SPEED as the belt. So how can that be the same speed as the belt, while also being the same speed of the belt if it stays at the midpoint of the frame and doesn't move forward or backwards as the belt travels around????? That's claiming two different scenarios BOTH mean the craft is traveling the same speed as the belt! NOT!

    The craft absolutely does NOT extract power from the air. ALL the power is coming from the outlet! If you think the craft extracts power from the air then why can't the craft do that while the treadmill is unplugged? Why can't you just set a craft on a table and the craft extract power from the air? Watts=Amps x Volts, and in this case, ALL the power is coming from the outlet. IN NO WAY is the air doing work on the craft. The craft is doing work on the air! The craft gets the power to do work on the air from the belt, which gets its power from the outlet. The outlet is powering the entire work done. Again, you are claiming perpetual motion. You are claiming "free energy." I'm sure you know better than that, but you continue to say that!

    ...and how do you measure the speed of the belt? Do you measure the speed of the belt compared to the craft? So with no craft on the moving belt the belt speed is zero, according to you? If you acknowledge the speed of the belt is compared to the frame, then why would you then compare the speed of the craft to THE BELT and compare the two speeds?

    So you measure the belt against the frame, and the craft against the belt, and then compare them to see which is faster? That is absurd! You are comparing two entirely different scenarios and then claiming one is faster. You are testing a rabbit running uphill, and bullet from a gun, and claiming the orange is faster!
     
    Last edited by a moderator: May 3, 2022
  23. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    You can, assuming the "air" is moving in the direction of travel.

    If the wind is in the direction of travel, the wind pushes the vehicle forward. (F-wind = m*a). This is simply the wind pushing against the structure of the car.
    The tyre movement rotates the propeller (note that it is not the wind which rotates the propeller, but the motion of the tyres), which pushes air back, generating additional force (F-prop) causing the car to accelerate even more (F-net = F-wind + F-prop).
    Eventually the car will travel faster than the wind - e.g. if wind is 20 mph then the vehicle can go much faster than that in the direction of wind, before the drag of the vehicle, and friction, balances the forward forces. (F-net = F-wind + F-prop + F-drag + F-friction = 0).
    No motor, just wind power.
    Obviously if the wind then drops, the drag will gradually slow the vehicle down.

    I thought it explained it all in the video you linked in the OP, although it has been a while since I saw that one.
     
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