NameCLASSParti Theoretical Mechanics(叫恥)Cautions: ©This test paper contains two subjects, and you have 60 mins to finish this part. D ©Reassure that each question and every sketch arc answered in the right area.■ ■③The unit of length in this test is always mi 11 imeter unless special announcement©Every question with different styles of font means that this question is basic.1. (30 points)Suppose that all the systems are frictionless.Draw the FBD for each body•(①Dorft contain any supports ©Don't draw the FBD of the system)r12]2. (10 points)Here is a plank given in G-2,which is cut out of three very small circles named A,B ,C .Three forces are exerted separately on three circles.Vertical Fi=70 V3 N,Through line AB2F2=200N,Horizontal F3=25 —N.Find the resultant of this system.3. (10 points)题3图Hydraulic clamping refers to machine quick clamping device with hydraulic as power, which can be realized on a work-piece clamping action quick, saving a lot of manpower and time.It can be simplified as the following picture(Graph-3).We^ ve known that the structure remains equilibrium.And F is a given constant.Find the holding power acted by H to E.(B,C,E are movable hinges,D is hinge.)Fp=4kN , M = 2kN ，4. (10 poims)Ignore all the mass of beams, we've known that 纟 一 ^kN/mFLsssI = 2m , C is frictionless pin.Find the reaction of support A,B.5. (15 points)F]=150N,F2=200N,F3=300N,F=F, =200N,the angle are shown on the draft,do the reduction result of the whole force system to point O,the magnitude of resultant and the distance of the resultant between the acting point and O・6. (15 points)Here is a construction memberO-A-B-C-D, AB // y - axis, BC // x-axis. CD // y- axis,7. (10 points)P\case judge these following statements whether true or not,presenting your view by using tick or cross behind the statement.©Three coplanar that hold a body in equilibrium must be concurrent. ©Generally,Built-in Support has three reactions of support. ©Vectors can be divided into various kinds,among which,free vector is the most common one.Such as moment,force,velocity,acceleration ④ If we move one couples from the top of body to the bottom of the same body,ifs equivalent. ⑤ A force at a given point can always be placed by a force at a different point and a couple-vector that isparallel with the force. 。