It is known that a force with a moment of 960 N · m about D is required to straighten the fence post CD. If the capacity of winch puller AB is 2400 N, determine the minimum value of distance d to create the specified moment about Point D.
Draw the free-body diagram of the fence post:
From the geometry of the figure, state as follows:
Here, the angle between ED and EC is and the distance between E and D is.
Consider the equilibrium of moments about point .
Here, the moment acting at D is and the maximum tension in cable BC is .
Substitute and in the above equation,
Solve the above quadratic equation for the value of d.
From the above data, the value of d should not be negative in sign. Hence, the value is.
Therefore, the minimum value of distance d to create a specified moment about the point D is .