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 Jun 6th 2017, 06:51 AM #11 Junior Member   Join Date: May 2017 Posts: 16 reply to Mr chip Hello Mr.chip, Do you have any difficulty to understand it ?tell me I 'm ready to send you more information . Vikram
 Jun 6th 2017, 06:52 AM #12 Junior Member   Join Date: May 2017 Posts: 16 Hello Mr.chip, Do you have any difficulty to understand it ?tell me I 'm ready to send you more information . Vikram
 Jun 6th 2017, 10:48 AM #13 Physics Team     Join Date: Jun 2010 Location: Naperville, IL USA Posts: 2,233 Please see my attached figure and clarify the parts that aren't correct. In step 1 the ball is on the right seesaw, above the pivot point, with zero velocity. It starts to roll downhill towards the left. It descends a height h, giving it an initial velocity according to energy principles of $\displaystyle V_i = \sqrt {2 g h}$ In step 2 it is crossing the bridge, and in step 3 the ball is on the left seesaw, still moving with velocity $\displaystyle V_i$. In step 4 the left seesaw tilts while the ball is still to the right of the pivot point. This causes the ball to drop in elevation - and this is where the mechanism fails. The ball now must roll uphill. In step 5 the ball has rolled up the left seesaw, but given its initial velocity $\displaystyle V_i$ has enough momentum to roll up height h. which brings it up only to the pivot point, but no more than that. When it reaches the pivot point it has zero velocity. In step 6 the bridge shifts to the left, and the right seesaw becomes level. But the ball is at the same elevation as the bridge, and so has no velocity with which to roll to the right. Attached Thumbnails
 Jun 6th 2017, 08:41 PM #14 Junior Member   Join Date: May 2017 Posts: 16 Dear Mr Chip, I know about it but I have already provide a solution (a lock system)and this lock system will work to lock the left seesaw before loading the mass and unlock at the time of transporting the ball.this lock system will work to lock the seesaw to prevent it to get flipped down and will consume only 1 or 2 joule energy.the total input+mechanical losses will be 5 to 10 joule maximum but output will be more than input when we take ball mass 20 kilogram and lift up seesaw arm up to 20 centimeter height after using potential energy formula.it will be 40 joule.
 Jun 7th 2017, 04:48 AM #15 Physics Team     Join Date: Jun 2010 Location: Naperville, IL USA Posts: 2,233 It's not a question of how a locking mechanism would work - I'm just trying to understand the motion of the ball. Where exactly is the ball at the moment the left seesaw tilts? I showed it as step 4 - are you suggesting the tilting occurs later? 1. If the ball is to the right of the pivot at that instant then the ball must lose some kinetic energy as it rolls uphill. Which means on each cycle it loses more and more KE. 2. If it's to the left of the pivot then the seesaw is not in balance, so energy is requiredf to tilt the seesaw and raise both the ball and counterweight. 3. If it's precisley at the pivot energy will again be required to tilt the seesaw. So, which is it? Last edited by ChipB; Jun 8th 2017 at 11:22 AM.
 Jun 7th 2017, 06:15 AM #16 Junior Member   Join Date: May 2017 Posts: 16 Dear Mr Chip, The tilting will be occurred after the ball will completes it's momentum or after stopping.
Jun 7th 2017, 07:06 AM   #17
Physics Team

Join Date: Jun 2010
Location: Naperville, IL USA
Posts: 2,233
 Originally Posted by vkrmvkrm11 Dear Mr Chip, The tilting will be occurred after the ball will completes it's momentum or after stopping.
In my sketch I show the left seesaw is initially level, not tilted, when the ball reaches it - is that correct? Please draw a sketch showing how the ball comes to rest on the left seesaw without it tilting.

 Jun 7th 2017, 09:39 AM #18 Junior Member   Join Date: May 2017 Posts: 16 The ball comes to the rest without tilting the Left seesaw. I have told you that a lock system will work here to prevent the left seesaw when ball will be loaded on it.you can imagine this lock system as a iron rod and this iron rod will work as a brake to prevent it from tilting down due to mass and distance from fulcrum.when ball comes to rest then this lock will be removed and left seesaw will be ready to transport the ball towards right side seesaw.
 Jun 7th 2017, 09:41 AM #19 Junior Member   Join Date: May 2017 Posts: 16 This lock system will work to lock the seesaws before unloading the ball.
 Jun 7th 2017, 01:22 PM #20 Physics Team     Join Date: Jun 2010 Location: Naperville, IL USA Posts: 2,233 Sorry vkrm, but you are being so unclear about what causes the ball to stop and reverse course that there's not much point in continuing this conversation. If you would please answer the questions I have posed I will be happy to continue, but until then there's not much to discuss.

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