A block of mass M is placed on smooth
ground. Its upper surface is smooth and
vertical surface is rough with coefficient
of friction μ. A block of mass m_1 is placed
on its horizontal surface and tied with
a massless inextensible string passing
over smooth pulley. Its other end is
connected to another block of mass m_2 ,
which touches the vertical surface of
block M. Now a horizontal force F
starts acting on it.
Q1. Which of the following is incorrect
about above system?
(1) There exists a value of F at which
friction force is equal to zero
(2) When F = 0, the blocks cannot
remain stationary
(3) There exists two limiting values of
F at which the blocks m_1 and m_2 will
remain stationary w.r.t. block of mass
M
(4) The limiting friction between m_2
and M is independent of F
Q2. In the above case, let m_1 − μm_2 be
greater than 1. Choose the incorrect
value of F for which the blocks m_1 and
m_2 remain stationary with respect to
M
(1) (M + m_1 + m_2 )((m_2 g)/m_1 )
(2) ((m_2 (M + m_1 + m_2 ))/((m_1 − μm_2 )))g
(3) (((M + m_1 + m_2 )m_2 g)/((m_1 + μm_2 )))
(4) (M + m_1 + m_2 )(g/μ)
Q3. Let vertical part of block M be
smooth. Choose the correct alternative
(1) There exist two limiting values for
system to remain relatively at rest
(2) For one unique value of F, the blocks
m_1 and m_2 remain stationary with
respect to block M
(3) The blocks m_1 and m_2 cannot be in
equilibrium for any value of F
(4) There exists a range of mass M, for
which system remains stationary
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