Request a call back

Join NOW to get access to exclusive study material for best results

JEE Class main Answered

Plz solve it step by step making me understand the formula being applied here
question image
Asked by vishakhachandan026 | 23 Jul, 2019, 08:59: AM
answered-by-expert Expert Answer
Fig.1 shows  two rods which are inclined to vertical axis by 45°. Let length of each rod be l and mass of each rod be m.
 
Let us consider moment of inertial of small mass elements dm from both the rods,
which is of length dl' and at a distance l' from point O.
 
Moment of inertia dI about the axis passing through centre as shown in fig.1 is given by
 
dI = 2×dm×(l'/√2)2  = ( ρ×dl' )×(l')2
 where ρ is mass of rod per unit length.
 
Moment of inertia I of system of two rods about the axis passing through centre as shown in fig. 1 is given by
 
begin mathsize 14px style I space equals space rho integral subscript 0 superscript l l apostrophe squared d l apostrophe space space equals space rho l cubed over 3 space equals space left parenthesis space rho space l space right parenthesis space l squared over 3 space equals m l squared over 3 end style......................(1)
Moment of inertia I of system of four rods about the axis passing through centre as shown in fig. 2 is given by
 
I = m×(2/3)×l2 ...........................(2)
 
Moment of inertia I of system of four rods about the axis passing through corner as shown in fig. 3 is obtained
by applying parallel axis theorem.
 
Hence, noment of inertia I = m×(2/3)×l2 + 4m×(l/√2)2 =  (8/3)m×l2
Answered by Thiyagarajan K | 23 Jul, 2019, 02:30: PM
JEE main - Physics
Asked by chaudharyrakesh10312 | 19 May, 2024, 02:12: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by amanniju2 | 17 May, 2024, 09:00: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by sohan123asiwal | 12 May, 2024, 05:52: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by anupriya23102006 | 09 May, 2024, 04:09: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by ashwinskrishna2006 | 07 May, 2024, 05:33: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by srkgb8018 | 05 May, 2024, 10:12: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Asked by pkp7734825 | 04 May, 2024, 10:30: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×