Question

solve the pink one

Answer 1

Blue:
Denote tension in cord as T. Vertical reaction on bar equals weight of bar, assuming no friction anywhere.
Take moments about B. Solve for T.

Answer 2

how?

Answer 3

can you show to me

Answer 4

"How" meaning to take moments?

Answer 5

yes but i'm confuse >.<

Answer 6

roller gve vertical force to the wall so therefore

Answer 7

also

Answer 8

I can give an example:

A ladder 5 m long leans agains a smooth wall at B and stands on a rough floor at A at a distance of 3 m from the wall as shown above. The mass of the ladder is 10 kg.

Since we don't know the friction on the floor, we can take moments about A so the friction does not come in the equation.
Let reaction at B = R
Mass at the middle (C) = m
Take moments about A, since the ladder is in equilibrium, sum of moments = 0.
-R*4 + mg*(3/2)=0
Note: moment = force * distance, clockwise is positive.
Solve for R:
R=(3mg/2)/4, or =3mg/8 N.

Answer 9

yes u are right

Answer 10

So you're good for both problems?

Answer 11

no

Answer 12

lets continue master