How Do Tractor Forces Combine When Pulling at an Angle?

[balletprincess34]

two tractors pull against a 1750kg. if the angle of the tractors' chains in relation to each other is 36.0 degrees and each tractor pulls with a force of 8000N what is the total force exerted by the tractors

is the answer 15200N?

 

[andrewchang]

yes, approximately.

 

[balletprincess34]

thank u...i just wanted to double check :)

 

[Ouabache]

is the answer 15200N?

I am curious, how did you arrive at this answer?

 

[balletprincess34]

process of elimination, law of cosines, formula for calculating force weight...etc etc...

 

[andrewchang]

there was a fair amount of guessing about the question, but I think that it was asking what the resulting force on the object is. Then, if the tractors are pulling at a 36 degree angle from each other, they are pulling at a 18 degree angle from the horizontal (_assuming_ that they are aligned around the horizontal) From then, I just added the vectors. At least, I think that's what the question is asking.

 

[Ouabache]

process of elimination, law of cosines, formula for calculating force weight...etc etc...

Hmmmm, not sure how you derived 15,200N using those methods. Perhaps you can explain?

 

[Ouabache]

there was a fair amount of guessing about the question, but I think that it was asking what the resulting force on the object is. Then, if the tractors are pulling at a 36 degree angle from each other, they are pulling at a 18 degree angle from the horizontal (_assuming_ that they are aligned around the horizontal) From then, I just added the vectors. At least, I think that's what the question is asking.

In my interpretation of the question, I sense, if the tractor chains are pulling at 36 deg angle from each other, then they are each 18 deg from the vertical, meaning they are 72 deg from the horizontal.
Since you are only determining the total force exerted by the tractors (and ignoring the force exerted by gravity on the object with mass 1750kg), you can calculate the horizontal and vertical force components for each chain. The horizontal forces are equal and opposite in direction, so therefore cancel. That leaves the vertical component for each chain.

Just calculate one of them (Fy) and multiply by 2.
(Assuming that both tractors are taller than the mass their chains are attached to) Fy(total) = 2*(8000sin72) = 15217N in upward direction.


If you do take into account the vertical force of gravity on the 1750kg object, then what would be the total resultant force of the system? and in what direction?