In the figure shown below, all surfaces
are smooth, strings and pulley are ideal.
If the wedge is moving with acceleration
a towards the right, then the acceleration
of the block with respect to the wedge
at that instant is
In a fuel cell, methanol is used as a fuel
and O_2 is used as oxidizer. The standard
enthalpy of combustion of methanol is
−726 kJ mol^(−1) . The standard free
energies of formation of CH_3 OH(l),
CO_2 (g) and H_2 O(l) are −166.3, −394.4
and −237.1 kJ mol^(−1) respectively. The
standard internal energy change of the
cell reaction will be
The reversible expansion of an ideal
gas under adiabatic and isothermal
conditions is shown in the figure. Which
of the following statement(s) is (are)
correct?
(1) T_1 = T_2
(2) T_3 > T_1
(3) w_(isothermal) > w_(adiabatic)
(3) ΔU_(isothermal) > ΔU_(adiabatic)
Which of the following reaction is/are
exothermic reaction/s?
(1) CaCO_3 → CaO + CO_2
(2) Fe + S → FeS
(3) NaOH + HCl → NaCl + H_2 O
(4) CH_4 + O_2 → CO_2 + 2H_2 O.
(n − 1) equal point masses each of mass
m are placed at the vertices of a regular
n-polygon. The vacant vertex has a
position vector a with respect to the
centre of the polygon. Find the position
vector of centre of mass.
A block is released from rest at the
top of a frictionless incline
plane 16.00m long.It reaches the
bottom 4.0s later.A second block
is projected up the plane from the
bottom at the instant the first one
is released in such a way that it
returns to the bottom simultaneously
with the first block.Find:
a)the acceleration of each block
on the incline plane
b)the initial velocity of the first
block.
c)how far up the incline plane
did the second block travel.
d)What angle does the plane makes
with the horizontal.
(g=10m/s^2 )
A lorry goes round an unbanked
curve.If the radius of the curve
is 30m and the coefficient of
friction between the ground and
the tyre is 0.6. Calculate the
maximum speed of the lorry.
(g=10m/s^2 )
please buddies help
A plank of mass M kg is sliding on the
smooth horizontal surface with constant
velocity of 10 ms^(−1) . A another block of
mass M kg is gently placed on it. The
coefficient of friction between the
block and the upper surface of the plank
is 0.2. Assuming that plank is long
enough such that the block does not fall
from it. The velocity-time graph of the
block is [Take g = 10 m/s^2 ]
Five moles of an ideal gas expand
isothermally and reversibly from a
pressure of 10 atm to 2 atm at 300 K.
What is the largest mass (approx)
which can be lifted through a height of
1 m in this expansion?