# Physics doubt!

How to solve this? I understand that we need to use force as vdm/dt but the answer doesn't match?

Note by A Former Brilliant Member
4 years, 3 months ago

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Sort by:

- 4 years, 3 months ago

Hey, that was a nice question!

- 4 years, 3 months ago

Thanks.....try previous years inpho papers they are awesome.

- 4 years, 3 months ago

Yup, they are.

- 4 years, 3 months ago

ha! did it a long time ago ! :P

- 4 years, 3 months ago

I told you ....you are awesome in physics

- 4 years, 3 months ago

How to solve this? : momentum change= force :)

- 4 years, 3 months ago

But using this answer comes as hv^2

- 4 years, 3 months ago

which one is given as answer ?

- 4 years, 3 months ago

hv^2/2

- 4 years, 3 months ago

shit ! i wrote it on paper and clicked pic to show you , displaced the power cord a little and boom , computer off. after then solved 4 level 5's and wrote their solution , upvote them too :P le dekh le samaj aa gya ?

- 4 years, 3 months ago

Oye @A E

- 4 years, 3 months ago

- 4 years, 3 months ago

kidhar hai bhai ?

- 4 years, 3 months ago

Ghar pe.

- 4 years, 3 months ago

mera net slow hai :P pehle likha tha

- 4 years, 3 months ago

yeh question INPHO 2009 ka tha .

- 4 years, 3 months ago

oh ! samaj aa gya ke ?

- 4 years, 3 months ago

haan aa gya.....itna physics kaise aata hai bhai?????

- 4 years, 3 months ago

are mein to kuch bi nhi hue yaar , bhai hoga to yeh Q dubara mat poocheyo plz , meri padai ke mamle mein bezzati kr liya kr besak :) P.S i hardly studied today :P

- 4 years, 3 months ago

online whole day :(

- 4 years, 3 months ago

yeh 2nd solution mein 1/2 mv^2 ko kisse equate kiya hai....dikhai nahi de raha ?

- 4 years, 3 months ago

F*l ( force *length )

- 4 years, 3 months ago

achha thik hai..

- 4 years, 3 months ago

Ya I got kv^2/2.it will be misleading for many I guess to mark kv^2.but if the part held goes a distance of vt then the part coming to motion will have a length of vt/2.its quite apparent and easy to analyse if the part held goes vt then the part that will be available to come to motion must be vt as length is conserved but this appears in the curl with 2 half length of (vt/2)each!!!so now we can use f=vdm/dt =vd(kvt/2)/dt=kv^2/2.

- 4 years, 3 months ago

yaa ......great observation.

- 4 years, 3 months ago

And only one part of the curl will be in motion as the other will be with the ground itself.(so rest)☺☺

- 4 years, 3 months ago

The best part is I could perform this at home after solving.just take a slinky tie its end and make a curl and move it.you will get it.

- 4 years, 3 months ago

ok ....thanks for help!!!

- 4 years, 3 months ago

bas bi kar pura lecture lagaega kya ? :P

- 4 years, 3 months ago

Don't mind your handwriting isn't good.although legible

- 4 years, 3 months ago

achha thik hai. :(

- 4 years, 3 months ago

Ab handwriting pe fight mat karo bhaiyon...

- 4 years, 3 months ago

maine to kuch kaha hi ni ! , koi aur question de na yaar :)

- 4 years, 3 months ago

Ruk kaal Deta hoon a hi mai abhi sone jaa raha hoon !!!!

- 4 years, 3 months ago

kai saarre laio , waisse toh mujhe module bhi shuru kar ne hai , phir bhi :)

- 4 years, 3 months ago

Yaa.... sure

- 4 years, 3 months ago

l'm the only one from my center not to even start doing my coaching modules while others have finished it :\

- 4 years, 3 months ago

Modules se accha hai kuch achhe books karna ,uske bad modules relatively easy lagenge....

- 4 years, 3 months ago

abe time kaha hai ? ab to cbse aur 2 ko mains :!

- 4 years, 3 months ago

Bas Chem hi bacha hoga na ?

- 4 years, 3 months ago

sare subject , mera bura haal hai ::

- 4 years, 3 months ago

OK then all the best.....be positive mains accha hoga aur adv bhi

- 4 years, 3 months ago

thnx bhai , as long as bhais like you r around me no mains-advance can stop me :) (hopefully:P)

- 4 years, 3 months ago

Yes ....study hard you will rock both the exams. Good night.

- 4 years, 3 months ago

yep gd........tc :D

- 4 years, 3 months ago