I need an answer fast plz

L = 1.5 [m]

Explanation:

To find the Force Z we must perform a sum of forces on the Y-axis equal to zero, (it is equal to zero since there is no movement, the beam is in equilibrium).

ΣFy = 0

- 30 - 20 - 40 + Z = 0

Z = 90 [N]

Now to find the length of the beam, we must perform a sum of moments equal to zero at the midpoint of the beam, where the load Z is applied.it is important to clarify that the moment generated by the force of 30[N] tends to rotate the beam counterclockwise (is taken as positive), while the load of 20 [N], tends to rotate the beam Clockwise (is taken as negative).

ΣM = 0

+ (30*0.5) - (20*x) = 0

15 = 20*x

x = 15/20

x = 0.75 [m] (this is the half of the distance)

L = 2*x

L = 2*0.75

L = 1.5 [m]

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.