winch snatch block storage question

[stumps]

That depends on whether thing 1 is moving towards the tree.

I think that either way, the truck pulls on the tree with the same force that the tree pulls on the truck. It's a characteristic of rope.

If the tree has a better grip on the ground than the truck, the truck may be moving towards the tree.... or vice versa.

-Chuck

 

[Bighurt]

I think that either way, the truck pulls on the tree with the same force that the tree pulls on the truck. It's a characteristic of rope.

If the tree has a better grip on the ground than the truck, the truck may be moving towards the tree.... or vice versa.

-Chuck

Considering that the pulling power of thing 1 is greater than thing 2 only when the power exerted by thing 1 exceeds the friction thing 2 exerts on the ground.

Then the friction the tree exerts on the ground (IE holding power of the roots) must be over come by the pulling force of thing 1, same as thing 1 must exert more pulling power on the tree than the friction of the tree to the earth.

The characteristic of the rope is that it must withstand the combination of the two opposing forces.

Or think of it this way when thing 1 and thing 2 are having a tug of war neither can can move the other until the pulling force exceeds the others holding force, therefore pulling and holding a term for the same force at different places on the scale of energy.

Course now there are so many factors in the equation its pointless.

 

[mudguppy]

the plane flies.

 

[stumps]

Or think of it this way when thing 1 and thing 2 are having a tug of war neither can can move the other until the pulling force exceeds the others holding force, therefore pulling and holding a term for the same force at different places on the scale of energy.

Course now there are so many factors in the equation its pointless.

The question was if the truck is pulling on the tree with 2 x Thing1 force, how hard is the tree pulling on the truck?

And the answer is exactly as hard as the truck is pulling on the tree.

If that isn't true, then there isn't a taut rope between the truck and the tree.

-Chuck

 

[Bighurt]

The question was if the truck is pulling on the tree with 2 x Thing1 force, how hard is the tree pulling on the truck?

And the answer is exactly as hard as the truck is pulling on the tree.

If that isn't true, then there isn't a taut rope between the truck and the tree.

-Chuck

But if the truck pulls on the tree harder than then the tree pulls on the truck the tree is pulled from the earth. If the tree pulls on the truck harder the winch winds up and drags the truck to the tree...

 

[mudguppy]

seriously?

 

[wldrbob]

ya had the tree let go a few times lol

 

[fasttruck]

Remeber, there are never just "one" block. I believe the capstan of the winch counts as a pully also.

 

[stumps]

But if the truck pulls on the tree harder than then the tree pulls on the truck the tree is pulled from the earth. If the tree pulls on the truck harder the winch winds up and drags the truck to the tree...

It doesn't matter. They still have to pull equally hard.

One object may have the capability of pulling harder, but it can't tension the rope any harder than the object on the other end pulls back.

Change the direction of the problem to lifting. Assuming everything is steady state (eg. you aren't accelerating.) If you have a brick at the end of a massless rope, the maximum force you can pull on the rope is exactly the weight of the brick... which is also the maximum force the brick can pull on the rope.

This is always true when the rope is taut.

-Chuck

 

[greenjeepster]

ya had the tree let go a few times lol

Like this:
[media]http://www.youtube.com/watch?v=47EEkq4ehlE[/media]

 

[KsM715]

the plane flies.

Only if the runway remains stationary and does not accelerate in the opposite direction at the same speed the plane it traveling.

 

[mudguppy]

still flies.