IIT JEE , AIEEE Forum - Physics , Mechanics

djdylan2000

Question on HC Verma pg 50, Objective I, Q13.

I'm getting the answer as 2ucos(theta) and not u/cos(theta). Can someone explain the solution of the problem?

Rates guaranteed.

deedee

u might hav done a mistake while takin those vel in d given direction they ru/cos@ n nt ucos@

just drw d dia and find out

djdylan2000

didn't understand how u get u/cos@. If vel of each rope is u, then why the vertical component doesn't become ucos@?

Decoder

same problem used to happen to me...
actually take velocity of block as v..
now velocity component along string shud be vcos@..

by constraint velocities along strings must be same..
so u= vcos@..
so v = u / cos@..

wat u r doing is taking components of velocity of strings and adding them..which seems satisfying but is not..

rathin_123

for inclind string along the string both the blocks have samw velocity.

thus suppose velocity of mass M block is v.

this block's string along velocity is vcos@

so vcos@=u

thus v=u/cos@

djdylan2000

Thanx guys. a rate for both of u.

Ask & Discuss Questions with Community & Experts