What Happens to Torque as the Wrench Lowers?

[epheterson]

1. The Funny Intro:

The summer before he entered high school, Prof. Schueller’s had to run the farm because
his father had an emergency appendectomy. To adjust the “thread” (the width between
the wheels) of a John Deere 4020 tractor, a torque of about 1600 ft-lbs. was needed to
loosen the rusted clamping bolts.

Real Question: With given force and torque arm, how far many degrees past horizontal axis will the bolt turn?

2. What I got

I'm on the last part of the problem here, I have a 6-ft. arm producing 1800 ft.-lb. of Torque.

3. Where I am

I know the 1600 ft-lbs. are used simply to loosen the bolt, but I'm unclear exactly how to measure the degrees the resulting 200 ft-lbs. turns the bolt.





I'm hoping this is an easy one for you guys but he didn't mention a situation like this in class and I don't see the solution in the book. Any help is appreciated :).

For the fun of it, I included the picture my professor drew.

As always, much thanks!

 

[Doc Al]

Looks like you aren't given enough information. Did you post the question word for word as it was given?

Perhaps they are looking for the angle at which the torque drops below 1600 ft-lbs.

 

[epheterson]

I was getting the feeling that I'm lacking information too.

Verbatim: Assume that “x” = 6 ft. If Ed stands at “x” and Schueller at “x/2” and they start at a horizontal position, how far (phi in degrees) will they be able to turn the bolts?

Ed weighs 250 lb, and Schueller weighs 100

Is this what you were talking about, Doc Al?


Attached PDF so it can be very clear.

 

[Doc Al]

OK, the best you can do is what I had suggested. As the bolt begins to turn and the wrench lowers, what happens to the torque that is exerted by the men? Find the angle at which the torque is no longer enough to turn the bolt.