Download Name: your 800#: Test #1 MEGR 2141 Dr. Tkacik 7 February 2012

Name:__________________________________ your 800#: _____________________
Test #1
MEGR 2141
Dr. Tkacik
7 February 2012
What are the middle three numbers of your UNCC 800 number? Q= ______________
Problem #1). Calculate the force
and moment reactions at the bolted
base O of the overhead traffic-signal assembly. Each traffic signal weighs 80
lb, while the weights of the members OC and AC are “Q” lb (at G) and 120 lb
respectively.
“Q” lb
Problem #2) The small sailboat may be tipped at its
moorings as shown to effect repairs below the
waterline. One attached rope is passed under the
keel and secured to the dock. The other rope is
attached to the mast and used to tip the boat. The
boat has a total displacement with is equal to
the total mass of 5000 kg with a mass center
at G. The metacenter M is the point on the
boat through which the vertical resultant of the
buoyant forces passes, and GM is 0.8 m. Calculate
the tension required to hold the boat in the position
shown.
Problem #3) Determine the external reactions at A and F for the roof truss loaded as shown.
The vertical loads represent the effects of the supported roofing materials, while the diagonal
‘Q’ load force represents a wind load. ‘Q’ is your middle three 800 numbers in Newtons (N).
3a. Complete the Free Body Diagram
3b. What are the i and j components of ‘Q’?
3c. Write the Y equilibrium equation
ΣFy = 0 = ? =
3d. ΣMA = 0 = ? =
3e. Vertical force at point F = Fy = ? =
3f. Ay = ? =
3g. Ax = ? =
3h. Fx = ? =
Q (N)