EXP1: Triangle Law of Forces & Parallelogram of Forces

• Theory:

Depe.nding to t.he gen.eral la.w of the fo.rces , if t.he bo.dy ex.pose w.ith thr.ee for.ces in equi.librium th..an , the. tw.o. for.ces. are. repr.esented. as a t.wo s.ide of a tria.ngle. in sam.e. or.d..er w.ith sca.ling.th.eir mag.nitude.to a su.it.able sc.ale. th.en th.e th.ird. si.de o.r th.e closi.ng. si.de. of th.e trian.gle. wo.uld. b.e t.he resul.tant.in oppo.site. ord.er..

• Objective:

To provethe theoryforthe Triangle ofForces&Parallelogram ofForces.

• Apparatus:

Work panel, Weight with hangers, Magnetic protect.

• Procedure: part A (Known forces)

1) 100 gm weight has been added to the left and right hand weight hangers.

2)Than, 100 gm weight has been added to the center weight hanger.

3) after that, chord has been horizontally to measure the angel by protector.

4)space diagram of the chord has been drawing with the corrected angel.

5) force angel drawing that the length has been equalto the force because weight.

6)finally , the end of triangle has been meted with start point.( Figure 1.1)

Figure 1.1:  space diagram & force diagram for triangle of forces

• Procedure: part B (Unknown force)

1) Procedure of part a has been repeated .

2)Than, weight on any one of hungers has been added or removed and do not count weight. ( unknown weight.

3) continue with same procedure of part A.

• Procedure: part C (parallelogram of forces)

1) space diagram has been draw of the cord with correct Angeles.

2)force magnitudes has been marked on the space diagram.

3) the parallelogram has been constructed to find line OD .(Figure 1.2)

4)resultant. OD has been conformed.is equal.and opposite.to the.force.from.middle.

Figure 1.2:  parallelogram of forces

Observations and callculation:

Part a:

Scale – 5 cm and R = 5 cm

So , convert to N

5*5 = 25g

25/ 9.8 = 2.55 N

Part B:

Scale = 5 cm and R (unknown) = 4 cm

So,

5*4 = 20 g

20/ 9.8 = 2.04 N

Part C:

• Discussion:

Fin.ally, w.e fig.ure o.ut th.at i.f. tw.o for.ces, wh.ich. a.ct. a.t a po.int, w.e repre.sented. in mag.nitude. an.d direc.tion. b.y th.e t.wo. adj.acent. sid.es. o.f a para.llelogram. dr.awn. fr.om. o.ne. o.f it.s ang.ular. poi.nts, th.eir. resu.ltant. is repre.sented. b.y t.he dia.gonal. o.f t.he. paralle.logram. pa.ssing. thro.ugh. th.at ang.ular. poi.nt, in mag.nitude. a.nd dir.ection. Th.ere i.s n.o err.ors i.n measur.ement.