Old Exam Papers Dec. 2010 - Video

(b) Show that the length of an endless chain which will
hang over a circular pulley of radius a so as to be in
contact with two thirds of the circumference of the
pulley is :
L
M
N
a 4?
3
? M3
logd2 ? 3i
O
P
QP
iznf'kZr dhft;s fd ,d fcuk fljs dh cUn tathj tks
f=T;k a dh ,d o`Ùkkdkj f?kjuh ds 2
3
esa gS] rks mldh yEckbZ gksxh %
L
M
N
a 4?
3
? M3
logd2 ? 3i
O
P
QP
Hkkx ds lEidZ
4. (a) The position of a moving point at time t is given by
x ? a cos wt , y ? a sinwt
, find its path, velocity
and acceleration at time t.
fdlh xfreku fcUnq dh t le; ij fLFkfr
x ? a cos wt , y ? a sinwt
gSA bldk fcUnq iFk t le;
ij blds osx rFkk Roj.k Kkr dhft;sA
(b) A point moves in a curve so that its tangential and
600 4 MT-09
Papers (A) (December) 2010
(369)
Roj.k f ft/sec 2 gSA fl) dhft;s fd batu dh izHkkoh
v'o 'kfä gS %
b g
mv nf ? g
550 ng
(b) A spider hangs from the ceiling by a thread of modulus
of elasticity equal to its weight. Show that it can climb
to the ceiling with an expenditure of work equal to
only three quarters of what would be required, if the
thread were inelastic.
,d edM+h dejs dh Nr ls ,d ,sls /kkxs ls yVdrh gS
ftldk izR;kLFk ekikad mlds Hkkj ds cjkcj gSA fl)
dhft;s fd og ml dk;Z dk 3
Hkkx djds Nr rd p