how would u drw this?

Question

i have to diagram the following arrangement in a block on a piece of paper: a uniform bar AB weighing 6N, is 1m long and rotates about a fixed point C, which is 40 cm from AB. a weight of 3N is attached at A and an unknown weight is attached at B to produce equilibrium.
i dont know hot to draw the alst two parts of that where would i draw the weight of 3N and the unknown weight which will produce equilibrium if u knwo any sites that go in detail on this plz let me know...thanks

Answer 1

Ok, it's not that difficult :

First draw the bar, that is 1 meter long.

Then draw the point "C" that is 40 cm from A, near the middle of the bar, but is closer to A.

The weight attached at A, just draw a short string down point A, and draw a block with 3 N weight.

The other weight attached to B, is practically the same, draw a short string down B, and draw a little block..

Now, if you wanna find the unknown weight :

Just applying torques, because the bar could rotate around C, but is on equilibrium, then :

(mass in A)*(40/100) = (mass in B)*(60 / 100) + 6*(10/100)

40 cm, is the distance from A to C

60 cm, is the distance from B to C

10 cm, is the distance from the center of mass of the bar to C, because the center of mass of the bar is on the middle, and C, is at 10 cm from the middle.

3*40 = x*60 + 6*10

60 = x*60

x = 1 Newton

The unknown weight is of 1 N