* 306s If (12040)

EM 306s (12040) Statics and Dynamics
Midterm Exam
Feb. 20, 1989
. .. . .
Time: 55 minutes
Closed book, closed notes
Show dl your work in a step by step fashion and follow the format as specified for
the homework.
If you have no time to complete all the cornputations, write down the procedure to do it.
I. The two forces acting on the handles of the pipe
wrenches constitute a coupIe M . Express the couple as a vector.
(20 points)
(25 points) 2. A force P of magnitude 90 Ib. is applied to the angle
AB which is supported by a frictionless pin at ID and by cable ACB.
The cabIe passes over the pulley at C. Determine the tension in the
cable and the reaction at D when a=3 in.
I- 5
I 7 in. j--..:\.
(25 points) 3. Two forces of magnitude P act along the diagonals of
the faces of a cube of side length a as shown.
(a) Replace the two forces by a system consisting of a singIe force at
0 and a couple.
(b) Find the vector component of the couple in the direction of the
resultant force.
(30 points) 4. The 23-kg pIate ABCD measures 325 by 450 mm; it
is held by hinges along edge AD and the wire BE. Determine the
tension in the wire.