11
Sorry abt the first eqn
17 Answers
62aragon.. you are partly right.
but if you "ignore rotatin", which you have to in this cae then only you will get the constraint equation as what is done by asish
sorry for the typo
I think virang has made some mistake.. i overlooked that one
11let M move a distance x.
Therefore first the longest string will move by x distance.
Pulling thestring on the otherside of the pulley by x
This the second pulley is pulled up by x . The second string joining M will have to move 2x to keep the M at x level. Therefore the string between the second and first pulley will also move by 2x. This will pull the first puley up by 2x. Therefore now the first(smallest) string attached M will move 3x to keep the M at x level . So will m move 3x
11Constraint:
if M moves down by l, then 2nd pulley moves up by l and the string in the second pulley moves to the right by l/2......similarly the string attached to m, moves up by l/4
Thus if acc. of M is a, acc. of m is a/4
(sorry for the bad english but pls adjust)
62aragon.. you are partly right.
but if you ginorerotatin, which you have to in this cae then only you will get the constraint equation as what is done by asish and virang.
106So, Mg - 7T = Ma ... (i) a = acceleration of M
T-mg = 7ma .. (ii)
Solving them,
Mg-7mg = Ma + 49ma
==> a = (M-7m)g/(m+49m) = aM
so, am = 7(M-7m)g/(m+49m)
106Constraint:
Let M move dx down and let m move dy up..
Work done by tension = 0 on system
So, T*dy - 7T*dx =0
==> dy=7dx
==> am = 7aM
11If acc of M is 4a, won't acc of m be a?? (applying constraints)
11Oi...i've had my names distorted before this,......but Strider---> stringer is the worst distortion!!! [16]
11First m
T - mg = 3ma
Therefore tension in the string between the first and second is 2T
Tension in the string between the second and third is 4T
Therefore the total force trying to pull M is T+2T+4T = 7T
Mg - 7T = Ma
T = ma+mg
Mg - 21ma - 7mg = Ma
g(M - 7m) = Ma + 21ma
g(M-7m) = a ( M + 21m)
a = g(M-7m)/( M + 21m)
11So we have to consider the rotation as well??
But as i said nothing else is given!!!