Faculty of Manufacturing Engineering University Malaysia Pahang 11 November 2016
BFF 2821 Mechanics Lab rian!"e o# Forces
Muhammad Zakuan Bin Abdul Rahman FA14040
[email protected]
Abstract This paper documents the experiments work carried out to study of sing ng so some me Tria iang ngle le of For orce cess by usi appara app aratus tus in the lab. In thi thiss activi activity ty participants will be explained about the three non!parallel forces in e"uilibrium that represented by a triangle of forces using a simple experiment.
2. Objective *he o b+ e c t i ( e of this e,periment e,perim ent are to (erif the law of tria triang ngle le of forc forces es b us usin ing g forc forcee board& boa rd& -ther -th er than tha n that! tha t! to sho show w tha thatt th thee thre threee non. non.p par aral alle lell fo forrce cess in e"uilibrium can be represented b a tri triangl anglee of for forces ces /pro(i /pro(ided ded that that the direction of forces is known&
3. Apparatus
1. Introduction Law of triangle of forces states that if three forces acting at a point can be represented in magnitude and direction b the sides of a triangle in the same order! then these three forces will be in e"uilibrium#1$#%$& 'on(ersel! the law of e"uilibrium can be stated that if three forces acting at a point are in e"uilibrium! then the can be represented in magnitude and direction b three sides of a triangle in the same order#)$&
*ABL 1 L23* AARA*53
4. Procedure *he diagram board was posit positioned ioned and secured with screws and nuts through holes on the mounting panel&
A&*est 1 *he thr three ee pul pulle less are pos positi itione oned d and secured with nuts as shown in Figure 1& A sheet of paper is clipped to the diagram board& *wo *wo of the ring cord is passed o(er the upper pulles and the weight hooks are attached to the end of them& Another weight hook is attached to the third cord& 6eights is added to the cords to achie(e %&78! )&%8 and %&%8 respecti(el& *he ring is released and the weights settled freel& *he position of the three cords is marked with pencil dots on the paper& *he paper is remo(ed! the lines is draw representing the three cords! and the weight supported b each cord is wrote&
Force 9iagram
B& *est % A new sheet of paper is clipped to the diagram board&*he weights is kept the same as in *est 1& *he ring is let to be balanced at the t he center of paper& After that! tha t! the center center weight weight cord is passed passed o(er the lower pulle as shown in Figure %& *he new position of three cords is marked and the line is draw representing th thee cord cordss as in *est 1& *he *he weig weight ht supported b each cord is recorded&
est 2 &
Free Bod 9iagram
Force 9iagram
$. %esu"t est 1 &
Free Bod 9iagram
%
'. (iscussion Based Based on our results results obtained! obtained! write our answers for the following "uestions 1& Fro From m our our force force diagram diagram drawn! st state ate how to find find th thee magn magnitu itude de of two component forces when the third one is known& . -ne -ne met etho hod d of de dete term rmin inin ing g th thee (ector sum of these three forces is to empl em plo o th thee meth method od of he head ad.to .to.t .tai aill addition& 2n this method! an accuratel dr draw awn n sc scal aled ed di diag agra ram m is us used ed an and d ea each ch in indi di(id (idua uall (e (ecto ctorr is drawn drawn to scale& 6here the head of one (ector end ends! th thee ta tail il of th thee ne,t e,t (ec ecto tor r begi ns& -nce -nc e all (ector (ec torss are added! adde d! th thee resu resulta ltant nt ca can n be de deter termi mine ned d b drawing a (ector from the tail of the firs firstt (e (ect ctor or to th thee he head ad of th thee la last st (ector& *his procedure is shown in the resul esultt of te test st 1 and and %& *he *he th thre reee (ectors are added using the head.to. tail method&
#1$ R&& ?A *e,tbook of n ng ginee ineerring ing Mech Mechan anic ics? s?&& La,m La,mii ublications& #%$ @err insberg/1CC=>& DAd(anced engineering ing dnami amicsE #% ed&$& 'ambridge 5ni(ersit ress& #)$ ra raham ham && DAd DAd(an (anced ced Gibration Gib ration AnalsisE& 'R' ress
%& 6hat 6hat do does es th thee tr tria iang ngle le of fo force rcess shows in addition to the magnitude magnitude of forces: . 2f ) forces acting at a point can be represented repres ented in si;e or direction b the si sides des of a cl close osed d tr trian iangle gle!! th then en th thee forces for ces are in e"uilib e"uilibrium rium!! pro(ide pro(ided d th thei eirr di dire recti ction onss can fo form rm a cl close osed d tri triang angle&* le&*his his means means that that the forces forces ca n f ol l o w e a c h o t h e r r ou n d a triangle&
). *onc"usion . *he triangle of force can be appl on three on.parallel on.parallel forces forces e"uilibrium e"uilibrium&& 2t can be concluded that! from this triangle! the magnitude of the resultant force can be determined using the law of cosines and its direction is determined from the la law w of si sine nes& s& *he *he magni agnitu tude de of two two forcess component force componentss are determined determined from the law of sines& *hus! it is pro(en&
8. %e#erences
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