Which is correct statement?
(1) The entropy of the universe increases
and tends towards the maximum
value
(2) All natural processes are irreversible
(3) For reversible isolated processes,
change of entropy is zero
(4) For irreversible expansion of
isolated processes, entropy change < 0
Show that volume of a region
of space bounded by a boundary
surface S is V= (1/3)∫∫_(S ) rcos θdA .
θ being the angle between the
position vector of a point P on
the surface, and the outer normal
to the surface at P.
r is the distance of point P from
origin.
Two blocks of masses 2 kg and 3 kg
are kept on a smooth inclined plane.
A constant force of magnitude 20 N is
applied on 2 kg block parallel to the
inclined. The contact force between
the two blocks is
A women swimming upstream is not
moving with respect to the ground. Is
she doing any work, if she stops
swimming and merely floats is work
done on her?
A 50 g lead bullet, sp. heat 0.02 is
initially at 30°C. It is fired vertically
upwards with a speed of 840 m/s and
on returning to the starting level strikes
a cake of ice at 0°C. How much ice is
melted? Assume that all energy is
spent in melting only (L = 80 cal/g).