# Gng1105 Final

Topics: Force, Trigraph, Mass Pages: 6 (757 words) Published: January 18, 2013
Universited'Otlawa
Faculte genie de
genie civil

University of Ottawa Faculty Engineering of

Departementde

u Ottawa

Department of Civil Engineering

GNG 1105
ENGINEERINGMECHANICS FinalExamination December9th,2011 Profs. A. Skaff Ph. Girault Y. Haddad and A. Ahmed Duration:3 hours Page:1 of 2 """C"

Closed bookexamination. Programmable calculators not allowed. are Free-body diagrams mustbe drawnwhereapplicable.

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Problem 1. (10/60)The truss shownis loadedby

two forcesP= 8 kN.Alljointsarepinned.
a) Determinethe reactionsat the supports0 and E. b) Usingthe method of sections,determine the forces in members BO, BE and CEin the truss, specifying for eachwhether it is in tension or compression. I

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Problem 2. (12/60) The diagramshowsa frame which is loaded by a force P =20 kN. All joints are frictionlesspins. Determinethe reactionsat A and D and all forces acting on member DEF.Note that members ABC and DEF are continuous solid members.

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Problem 3. (14/60) A 30 kg cover for a roof-opening

is hinged at corners A and B. The roof forms an angle of 300 with the horizontal, and the cover is maintainedin a horizontal position by the braceCEo Determine: (a) The magnitudeof the force exerted by the brace CE, (b) The reactionsat the hingesA & B. Assumethat the hinge at A doesnot exert any axialthrust. ~e,,=,

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Problem 4. (14/60) BlockA in the sketch hasa mass

of 20 kg and is attached to the wall by meansof a cord at an angleof 600with the vertical, while block B has a mass of 40 kg. The coefficient of static friction betweenA and B is 0.2, while the coefficient of static friction between B and the floor is 0.3. Determine the minimum force P required to cause BlockB to slide (i.e. Motion impending).

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Problem S. (10/60) A ball is thrown from the top of a 20m high tower with an initial velocity of Va= 10

m/s in the direction shown. (a) Determine the x and y coordinates of the point at which the ball strikesthe slope. (b) Determine the velocity of the ball at the point at which it strikesthe slope.

Page of2 2

Universite d'Ottawa Facultede genie

u Ottawa

ril

University of Ottawa
Facultyof Engineering

GNG 1505
Mecanique de l'ingenieur
&amen Final 9 Decembre 2011 Profs. Y. Haddad and E. van Blaeren Duree: 3 heures Page:1 de 2

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Examen a livre fenne. Lescalculatrices programmables sontpasadmises. ne Des schemas corpsrenduslibresdoiventette dessines de quandils sont applicables.

Probleme 1. (10/60) Le treillis illustre est chargeau
moyen de deux forces P

=8 kN.

Tous les nreuds sont

.2m

des rotules. a1 Determinez les reactions aux supports D et E. b). En utilisant la medlode des sections, determinez les forces dans les membrures BD, BE et CE du treillis en specifiant pour chacun si it est en tension ou en compress1on.

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3m

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Probleme 2. (12/60) Le diagrammemantle une cha.rpente chargee une force P = 20 kN. Tous les par nreuds sont des rotules sans &ottement Deter1'ninez les reactions en A et D ainsi que toutes les forces agissant sur les membrures DEF. Toutes les membrures ABC et DEF sont continues.

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Probleme 3. (14/60) Un panneau de couverture de toit de 30 kg pivote sur deux charnieresA and B. La pente du toit est de 300 par rapport a Phorizontale, et Ie panneau est maintenu dans une position horizontale par Ia barre CEo On suppose que Ia charniere A n'exerce aucunepousseeaxiale.Determinez: (a) L'intensite de la force exerceepar la barre CE, (b) La reactions aux charnieresA & B.

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Probleme 4. (14/60) Le bloc A a une massede 20 kg. II est attache au mur par une corde qui fait un angle de 600 avec la verticale. Le bloc B a une massede 40 kg. Le coefficient...