Problem #$4$

A traffic light consists of a horizontal member attached to a vertical support post. Each traffic

light has a mass of $m_1,$ and street sign has a mass of $m_2.$

$]=4m,B=[3m$

Analyze this system as follows:

a$.$ State the Givens, Finds and Assumptions.

b$.$ Draw a Free Body Diagram of the horizontal member and all forces acting on it $($ignore

reaction forces at $D,$ where the horizontal member attaches to the vertical pole$).$

c$.$ Write equilibrium equations, starting with equations in variable form.

d$.$ Replace the external forces due to the weight of the traffic lights and sign with an

equivalent force$-$couple resultant at D$.($DO NOT calculate the reaction forces at D$.$

NOTE: Weight forces are assumed to be vertical.$)$

e$.$ Replace the external forces by a single resultant force $($Do not include the reaction forces

at D$.)$ Specify where the resultant force acts along a horizontal line, measured from D$.$