I. All the three forces must be concurrent.
II. The upward force is equal to the downward force.
III. The algebraic sum of the moment about any point must be zero.
which of the above conditions must hold for a body acted upon by a system of three coplanar forces equilibrium?
I and II only
I and III only
II and III only
I, II and III
Explanation
Video Explanation
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Discussions (20)
I think the answer is D because
1. All the three forces must be concurrent that is they must meet at a point
2.The upward force must be equal to the downward force.we can simply resolve the three forces to upward and downward force and they must be equal
3. The algebraic sum of the moment about any point must be zero i.e when you resolve it
The answer should be B because they are talking about non parallel coplaner forces since they mentioned "three coplaner forces in equilibrium"
D i think will be the answere
The balancing force assumes the upward force then the two others are the downward force
My school is correct the answer is C, let me explain.
1.Coplanar forces: coplanar forces whose line of action lie on the same plane.
2.Concurrent force: these are forces which meet at one point.
3.Coplanar concurrent forces meet at a point and lie on the same plane.
Condition i is talking about coplanar forces
condition i and ii is talking about coplanar concurrent forces. so the correct answer is B.i andiii. My school answer is correct.
The answer is meant to be C. Condition (i) is not necessary in this case. Only few would understand
My school the word "WHY"again 😭😭,I got,I,II,III,.ANS:D.EVEN IN THE EXPLANATION VIDEO.THE TUTOR CHOSE D HAS IS ANSWER.please let correction made real quick
II. The upward force is equal to the downward force.
It is okay if you have 2 forces. But in given there are 3 coplanar forces. So, they act in 3 different directions
Pls the answer is B mychool pls change it, three coplanar forces cannot be resolved into upward and downward force, Pls correct it
how??? I have never heard of i before. So please explain where the idea is gotten from
