The Eduladder is a community of students, teachers, and programmers just interested to make you pass any exams. So we help you to solve your academic and programming questions fast.
In eduladder you can Ask,Answer,Listen,Earn and Download Questions and Question papers.
Watch related videos of your favorite subject.
Connect with students from different parts of the world.
Apply or Post Jobs, Courses ,Internships and Volunteering opportunity. For FREE
See Our team
Wondering how we keep quality?
Got unsolved questions? Ask Questions

Civil-engineering-Common-for-all-semester-->View question

State and prove parellelogram law of forces

Elements of civil engineering and engineering mechanics


Asked On2017-06-12 05:05:28 by:Aparna-Dasgupta

Taged users:
rathinlz04

Likes:
Be first to like this question

Dislikes:
Be first to dislike this question
Talk about this  Like  Dislike
View all qusetions
Answers

Prove the parallelogram law of forces:

Assume that the two forces and act at a point 'O' as shown in figure given below. The force can be represented in magnitude and direction by vector OA, While force is represented in magnitude and direction by vector OB, Angle between the two force is 'a'. The resultant can be denoted by vector OC as shown in the figure given below. Drop perpendicular from on OA.

Let,

P,= Forces whose resultant is needed to be found out.

θ= Angle that the resultant forces makes with one of the forces

α= Angle between the forces and Q

1071_Prove the parallelogram law of forces.png

It is the magnitude of resultant 'R'

 

2383_Prove the parallelogram law of forces1.png

Direction ( θ ):

865_Prove the parallelogram law of forces2.png

 

Conditions

(i) Resultant R is max when two forces collinear and are in the same direction.

 2380_Prove the parallelogram law of forces3.png

(ii) Resultant R is min when two forces collinear but acting in the opposite direction.

That is  α = 1800    =>   Rmin = PQ

(iii) If a = 900, that is when the forces act at right angle, then

=   P2  + Q2

(iv) If the two forces are equal that is, when Q  =>R = 2P.cos(θ/2)


Answerd on:2017-06-26 Answerd By:Amogh

Likes:
Be first to like this answer

Dislikes:
Be first to dislike this answer
Talk about this  Like  Dislike

You might like this video:Watch more here

Watch more videos from this user Here

Learn how to upload a video over here



Lets together make the web is a better place

We made eduladder by keeping the ideology of building a supermarket of all the educational material available under one roof. We are doing it with the help of individual contributors like you, interns and employees. So the resources you are looking for can be easily available and accessible also with the freedom of remix reuse and reshare our content under the terms of creative commons license with attribution required close.

You can also contribute to our vision of "Helping student to pass any exams" with these.
Answer a question: You can answer the questions not yet answered in eduladder.How to answer a question
Career: Work or do your internship with us.Work with us
Create a video: You can teach anything and everything each video should be less than five minutes should cover the idea less than five min.How to upload a video on eduladder