A system consists of three masses m1, m2 and m3 connected by a string passing over a pulley P. The mass m1 hangs freely and m2 and m3 are on a rough horizontal table (the coefficient of friction = μ). the pulley is frictionless and of negligible mass. The downward acceleration of mass m1 is,
C.
First of all consider the forces on the blocks,
For the 1st block,
mg - T1 = m x a ... (i)
Let us consider second and third block as a system,
Then,
T1 - 2μmg = 2m x a
mg ( 1 - 2μ) = 3m x a
A car of mass m is moving on a level circular track of radius R. If 
represents the static friction between the road and tyres of the car, the maximum speed of the car in circular motion is given by
D.
In this condition, centripetal force is equal to static frictional force between road and tyres,
so
A stone is dropped from a height h. It hits the ground with a certain momentum p. If the same stone is dropped from a height 100% more than the previous height, the momentum when it hits the ground will change by
68%
41%
200%
200%
B.
41%
A block A of mass m1 rests on a horizontal table. A light string connected to it passes over a frictionless pulley at the edge of the table and from its other end, another block B of mass m2 is suspended. The coefficient of kinetic friction between the block and the table is 
. When the block A is sliding on the table, the tension in the string is
C.
FBD of block A,
T -m1a = fk ..... (i)
FBD of block B
m2g -T = m2a ... (ii)
Adding Eqs. (i) and (ii), we get
m2g-m1a = m2a +fk
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