In a quadrilateral ABCD, it is given
that AB is parallel to CD and the
diagonals AC and BD are perpendicular
to each other.
Show that
(a) AD.BC ≥ AB.CD;
(b) AD + BC ≥ AB + CD.
A cylinder of weight 200 N is supported
on a smooth horizontal plane by a light
cord AC and pulled with force of 400 N.
The normal reaction at B is equal to
A ball of mass 400 g travels horizontally
along the ground and collides with a
wall. The velocity-time graph below
represents the motion of the ball for the
first 1.2 seconds.
The magnitude of average force between
the ball and the wall is
The coefficient of x^r in the expansion of
(1 − 2x)^(−1/2) is
(1) (((2r)!)/((r!)^2 ))
(2) (((2r)!)/(2^r (r!)^2 ))
(3) (((2r)!)/((r!)^2 2^(2r) ))
(4) (((2r)!)/(2^r (r + 1)!(r − 1)!))
Predict the density of Cs from the
density of the following elements
K 0.86 g/cm^3 Ca 1.548 g/cm^3
Sc 2.991 g/cm^3 Rb 1.532 g/cm^3
Sr 2.68 g/cm^3 Y 4.34 g/cm^3
Cs ? Ba 3.51 g/cm^3
La 6.16 g/cm^3
A ladder of mass m is leaning against a
wall. It is in static equilibrium making
an angle θ with the horizontal floor.
The coefficient of friction between the
wall and the ladder is μ_1 and that
between the floor and the ladder is μ_2 .
The normal reaction of the wall on the
ladder is N_1 and that of the floor is N_2 .
If the ladder is about to slip, then
(1) μ_1 = 0, μ_2 ≠ 0 and N_2 tan θ = mg/2
(2) μ_1 ≠ 0, μ_2 = 0 and N_1 tan θ = mg/2
(3) μ_1 ≠ 0, μ_2 ≠ 0 and N_2 = ((mg)/(1 + μ_1 μ_2 ))
(4) μ_1 = 0, μ_2 ≠ 0 and N_1 tan θ = ((mg)/2)
A force F^→ = 2xj^∧ newton acts in a region
where a particle moves anticlockwise
in a square loop of 2 m in x-y plane.
Calculate the total amount of work
done. Is this force a conservative force
or a non-conservative force?
If x^x ∙y^y ∙z^z = x^y ∙y^z ∙z^x = x^z ∙y^x ∙z^y such
that x, y and z are positive integers
greater than 1, then which of the
following cannot be true for any of the
possible value of x, y and z?
(1) xyz = 27
(2) xyz = 1728
(3) x + y + z = 32
(4) x + y + z = 12
Solve for real x:
(1/([x])) + (1/([2x])) = (x) + (1/3),
where [x] is the greatest integer less
than or equal to x and (x) = x − [x],
[e.g. [3.4] = 3 and (3.4) = 0.4].
A long plank begins to move at t = 0
and accelerates along a straight track
with a speed given by v = 2t^2 for 0 ≤ t
≤ 2. After 2 s, the plank continues to
move at the constant speed acquired.
A small block initially at rest on the
plank begins to slip at t = 1 s and stops
sliding at t = 3 s. Find the coefficient of
static and kinetic friction between the
block and the plank.
The standard heats of formation of at
298 K for CCl_4 (g), H_2 O(g), CO_2 (g) and
HCl(g) are −25.5, −57.8, −94.1 and
−22.1 kcal mol^(−1) respectively. Calculate
Δ_r H^⊝ for the reaction
CCl_4 (g) + 2H_2 O(g) → CO_2 (g) + 4HCl(g)
A cubical block is held stationary
against a rough wall by applying force
′F′ then incorrect statement among
the following is
(1) frictional force, f = Mg
(2) f = N, N is normal reaction
(3) F does not apply any torque
(4) N does not apply any torque