Two stones of masses m and 2m are whirled in horizontal circles, the heavier one in a radius $${r \over 2}$$ and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier stone when they exprience same centripetal forces. The value of n is
A
4
B
1
C
2
D
3
2
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30o, the box starts to slip and slides 4.0 m down the plank in 4.0 s.
The coefficients of static and kinetic friction between the box and the plank will be, respectively
A
0.5 and 0.6
B
0.4 and 0.3
C
0.6 and 0.6
D
0.6 and 0.5
3
AIPMT 2015 Cancelled Paper
MCQ (Single Correct Answer)
+4
-1
A block A of mass m1 rests on a horizontal table. A light string connected to it passes over a frictionless pully at the edge of 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 $$\mu $$k. When the block A is sliding on the table, the tension in the string is
Three blocks A, B and C, of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on the 4 kg block, then the contact force between A and B is
