Physics-
General
Easy
Question
Two particles A and B, each of mass m, are inter-connected by an inextensible such that the particle B hangs below a table as shown in the figure and particle A is on a rough rotating disc at a distance r from the axis of rotation of the disc. If the angular speed of the dis is 
, the frictional force developed at the interface of the particle & the disc is equal to
- mg/2
- < mg/2
- mg/
- zero
The correct answer is: zero
The particle of mass m experiences two forces (i) tension T (ii) frictional force f.
Þ Since the particle A is rotating in a circular path of radius r, its centripetal acceleration,
Þ r w2 = 
Putting T = mg for equilibrium of the mass B & w2 = g/r
we obtain f = mg – mr g/r = 0
Related Questions to study
Physics-
A uniform rope is moving with a constant acceleration ‘a’ on a smooth horizontal surface. The ratio of the tension in the rope at its mid point to the applied force is,
A uniform rope is moving with a constant acceleration ‘a’ on a smooth horizontal surface. The ratio of the tension in the rope at its mid point to the applied force is,
Physics-General
Physics-
A block of mass m slides down on a wedge of mass M as shown in figure. Let 
be the acceleration of the wedge and 
the acceleration of block. N1 is the normal relation between block and wedge and N2 the normal reaction between wedge and ground. Friction is absent everywhere. Select the correct alternative (s)
A block of mass m slides down on a wedge of mass M as shown in figure. Let be the acceleration of the wedge and the acceleration of block. N1 is the normal relation between block and wedge and N2 the normal reaction between wedge and ground. Friction is absent everywhere. Select the correct alternative (s)
Physics-General
Physics-
Two masses of 10 kg and 20 kg are connected by a light spring as shown. A force of 200 N acts on a 20 kg mass as shown. At a certain instant the acceleration of 10 kg mass is 12 ms-2.
Two masses of 10 kg and 20 kg are connected by a light spring as shown. A force of 200 N acts on a 20 kg mass as shown. At a certain instant the acceleration of 10 kg mass is 12 ms-2.
Physics-General
Physics-
The coefficient of friction of all the surfaces is 
. The string and the pulley are light. The blocks are moving with constant speed. Choose the correct statement
The coefficient of friction of all the surfaces is . The string and the pulley are light. The blocks are moving with constant speed. Choose the correct statement
Physics-General
Physics-
A force F is applied vertically upward to the pulley and it is observed that the pulley in the figure moves upward with a uniform velocity of 2 m/s. The possible value(s) of F is/are (in newtons)
A force F is applied vertically upward to the pulley and it is observed that the pulley in the figure moves upward with a uniform velocity of 2 m/s. The possible value(s) of F is/are (in newtons)
Physics-General
Physics-
Two blocks of masses m1 and m2 are connected through a massless inextensible string. Block of mass m1 is placed at the fixed rigid inclined surface while the block of mass m2 hanging at the other end of the string, which is passing through a fixed massless frictionless pulley shown in figure. The coefficient of static friction between the block and the inclined plane is 0.8. The system of masses m1 and m2 is released from rest.
Two blocks of masses m1 and m2 are connected through a massless inextensible string. Block of mass m1 is placed at the fixed rigid inclined surface while the block of mass m2 hanging at the other end of the string, which is passing through a fixed massless frictionless pulley shown in figure. The coefficient of static friction between the block and the inclined plane is 0.8. The system of masses m1 and m2 is released from rest.
Physics-General
Physics-
The figure shows a block of mass m placed on a smooth wedge of mass M. Calculate the value of M¢ and tension in the string, so that the block of mass m will move vertically downward with acceleration 10 m/s2
(Take g = 10 m/s2)
The figure shows a block of mass m placed on a smooth wedge of mass M. Calculate the value of M¢ and tension in the string, so that the block of mass m will move vertically downward with acceleration 10 m/s2
(Take g = 10 m/s2)
Physics-General
Physics-
In the figure, a man of true mass M is standing on a weighing machine placed in a cabin. The cabin is joined by a string with a body of mass m. Assuming no friction, and negligible mass of cabin and weighing machine, the measured mass of man is (normal force between the man and the machine is proportional to the mass)
In the figure, a man of true mass M is standing on a weighing machine placed in a cabin. The cabin is joined by a string with a body of mass m. Assuming no friction, and negligible mass of cabin and weighing machine, the measured mass of man is (normal force between the man and the machine is proportional to the mass)
Physics-General
Physics-
In the figure small block is kept on m then
In the figure small block is kept on m then
Physics-General
Maths-
In a sequence of (4n + 1) terms the first (2n + 1) terms are in AP whose common difference is 2 and the last (2n + 1) terms are in GP whose common ratio is 0.5. If the middle terms of the AP and GP are equal then the middle term of the sequence is
In a sequence of (4n + 1) terms the first (2n + 1) terms are in AP whose common difference is 2 and the last (2n + 1) terms are in GP whose common ratio is 0.5. If the middle terms of the AP and GP are equal then the middle term of the sequence is
Maths-General
Maths-
If 
and 
, then the minimum value of 
equals
If and , then the minimum value of equals
Maths-General
Maths-
If 
, then the value of 
is
If , then the value of is
Maths-General
Maths-
If 
, then 
is equal to
If , then is equal to
Maths-General
Maths-
The sum of 
is
The sum of is
Maths-General
Maths-
Maths-General
