Please wait...
Contact Us
Contact
Need assistance? Contact us on below numbers

For Study plan details

10:00 AM to 7:00 PM IST all days.

For Franchisee Enquiry

OR

or

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this number

93219 24448 / 99871 78554

Mon to Sat - 10 AM to 7 PM

How to solve this question?

qsnImg
Asked by anshadali111 7th May 2021, 4:08 PM
Answered by Expert
Answer:
Figure shows an equilateral triangle OAB and axis of rotation passes through a corner O.
 
Moment of inertia I of system about the given axis of rotation is given as
 
I = IAB + IOA + IOB
 
Where IAB Is moment of inertia of rod AB . Similarly moment of inertia of other two rods are considered.
 
Since thin rod AB is symmetrically placed about axis of rotation, we have
 
IAB = M × [ ( √3 /2 ) L ]= (3/4) M L2
 
Moment of inertia IOA of rod OA is determined as follows
 
Let ρ be the linear density of rod , ρ = ( M / L ) .
 
Let us consider small element of length dl in the rod at a distaance l along the rod from O as shown in figure.
 
Moment of inertia dI of this small element , dI = dm (l cos30)2 .
 
Moment of inertia of rod of full length OA is determined as
 
begin mathsize 14px style I subscript O A end subscript space equals space integral subscript 0 superscript L d m space r squared space equals space integral subscript 0 superscript L rho d l space left parenthesis space l space cos 30 space right parenthesis squared space equals space 3 over 4 rho integral subscript 0 superscript L l squared space d l space equals space 1 fourth open parentheses rho L close parentheses space L squared space equals space 1 fourth M L squared end style
Similarly we get , IOB = (1/4) M L2
 
I = IAB + IOA + IOB =  M L2 [ (3/4) + (1/4) + (1/4) ] = (5/4) M L2
Answered by Expert 7th May 2021, 6:18 PM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Your answer has been posted successfully!

Chat with us on WhatsApp