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###### Ram Prasath posted an Question
October 01, 2021 • 18:46 pm 30 points
• IIT JAM
• Physics (PH)

# Friends, explain this answer? why they put cos theta in it?

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• ##### Anshum Sharma

Ok, See abhi hum conservation of angular momentum lga rhe hai toh momentum hota hai ( p = mv) ab hme mass toh pta hai but velocity nhi pta ki kis direction mein hai wo hme find out krna hai, uske liye hum reference lete hai x and y axis ka abhi jo 2m and 3m hai wo x-y plane me hai unki specific Direction ni pta toh uske liye hum vector components ka law use krte hai wo aap attached image me dekh skte ho upper right corner me, toh us basis se 2m mass body move krri hai uske do components honge cos(theta) in the x direction or sin(theta) in y direction same in 3m mass also..... ye aap image me dekh skte ho ..... fr ab hum krte hai direction ki baat jisase unke sign pta chlege ab jo 2m or 3m hai unki direction hai towrds origin so unke components ki b direction hogi towrds origin, so diagram me dekho unki direction opposite to x and y axis hai us hisaab se unke signs diye hai... Got it .. I think simple way me apko smjha diya hai ....

it's really kind of u bro that u type this big paragraph. but i don't know hindi. sorry

• ##### Anshum Sharma

Here we resolve the components in x and y axis.... like as we resolve the vector components in cos(theta) and sin(theta)....Here the directions of 2m and 3m cos( theta) towards the (- x axis) so negative sign appear, In the sin(theta) component 3m towrds positive y axis and 2m towrds negative axis. . Got it? Now see the attached image for more understanding.

sorry bro, i still don't get it. where the -x axis came? and what is the sin and cos theta component?

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