Answer:
The answer is B) 5000 [N]
Explanation:
It needs to be assumed that the weight of the bridge is concentrated in the middle of the bridge, i.e. when the length is 2 [m]. A summation of moments around the pivot point must then be made, this sum equals zero. With the defined equation you can find the Force F, this force is the minimum to maintain the balance and the bridge in horizontal position.
The free-body diagram and the equation can be seen in the attached picture.
