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# resolving forces (CIE mechanics 1 ) watch

1. A barge of mass 4 tonnes is pulled in a straight line by two tugs with an acceleration of 0.6 ms^-2. The tension in one tow-rope is 1800N and the tension in the other is 1650N. Given that the angles the ropes make with the direction of motion are 20 degrees and X respectively, find angle X and the resistance to motion of the barge.
2. (Original post by Deffect)
A barge of mass 4 tonnes is pulled in a straight line by two tugs with an acceleration of 0.6 ms^-2. The tension in one tow-rope is 1800N and the tension in the other is 1650N. Given that the angles the ropes make with the direction of motion are 20 degrees and X respectively, find angle X and the resistance to motion of the barge.
Any thoughts? Attempts? Diagrams?
3. i don't know resisting dforces , two type of forces are unknown
4. (Original post by Deffect)
i don't know resisting dforces , two type of forces are unknown
Here's an overhead view of the situation.

I'd start by resolving forces perpendicular to the line of motion.

5. only horizontal motion in this question , ( tugboats can't rise it )
6. (Original post by Deffect)
only horizontal motion in this question , ( tugboats can't rise it )
Either you're trolling, or you have a problem with english.

It's an overhead view, i.e. as seen from above. Everything is taking place at ground level.

If you look at your own diagram, you have weight going down, so your "tugs" are flying!
7. my native language isn't English i'm in 9th grade in my country (English language is very weaker in my country ) ( i don't study igcse , in this year i started with math A level , this a first time in study mechanics)
i think upthrust force can ignored because a heavy barge ( but when i read it again ( in straight road )) so this is problem
8. (Original post by Deffect)
my native language isn't English i'm in 9th grade in my country (English language is very weaker in my country )
I suggest adding that to your profile so people are aware of it - currently there is nothing there.

( i don't study igcse , in this year i started with math A level , this a first time in study mechanics)
i think upthrust force can ignored because a heavy barge ( but when i read it again ( in straight road )) so this is problem
You need to look at the barge from above, as if in an aeroplane, or from the point of view of a bird flying overhead.

The barge is travelling in a straight line. The two tugs are pulling at an angle, one to the right, and one to the left.

The weight does not come into it. Although the mass does when considering the acceleration along the line of movement.
9. because in straight line so up thrust in one of tugboat will cancel by second boat
so 1800sin(20)/1650=sin(X) so x= 21.9077 degree
acceleration is 0.6 ms^-2 so 0.6*4*1000=1800cos (20)+1650cos(21.9077)-J, j=822.2935N
10. (Original post by Deffect)
because in straight line so up thrust in one of tugboat will cancel by second boat
so 1800sin(20)/1650=sin(X) so x= 21.9077 degree
acceleration is 0.6 ms^-2 so 0.6*4*1000=1800cos (20)+1650cos(21.9077)-J, j=822.2935N
Yes, those are the correct answers.

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