(D)
- Akash Anand Its not the right answer..try again.Upvote·0· Reply ·2013-03-13 22:37:52
- Akash Anand Actually answer is given C but I am also getting D. You people try once again.
(D)
12k(5mg/k)^{2} -12k(3mg/k)^{2} =12mv^{2}
from here we get v as 4gâˆšmk
(D)
Comment if I am wrong..
12K(6mgk)^{2}=12K(2mgk)^{2}+mg(8mgk)+12mv^{2}
let instantaneous extension be x' at time t=0^{2}
considering 3m block...having mg as normal reaction....
kx'+mg=3mg
kx'=2mg
x'=2mg/k
now...
(kx'^2)/2+(mv^2)/2 =0
taking mod value...nd solving v... we get v as 2g root (m/k)
answer--C