A cylindrical massless cord of length `l=10cm` and radius `r=3cm` is slowly extracted from the neck of a bottom opened bottle. If the normal pressure between the botle and un-extracted part of the cork at any instant is constant and equal to `P=(10^(5))/(pi)N//m^(2)`, find the work done (in Joule) in extracting it completely. The coefficient of friction between the cork and bottle is `mu=0.3`

A boy is pushing a ring of mass 2kg and radius 0.5 m with a stick as shown in figure. The stick applies a force of 2N on the ring and rolls it without slipping with an acceleration of 0.3 m/s^2. The coefficient of friction between the ground and the ring is large enough that rolling always occurs and the coefficient of friction between the stick and the ring of (P/10). The value of P is

A straight round copper conductor of radius R = 5.0 mm carries a current I = 50 A Find the potentail difference between the axis of the conductor and its surface. The concentration of the conduction electrons in copper is equal to n = 0.9.10^(33) cm^(-3) .

A body of mass 0.3 kg is taken up an inclined plane of length 10 m and height 5 m and then allowed to slide down to the bottom again. Coefficient of friction between the body and the plane is 0.15. What is the Work done against the frictional force over the round trip?

A body of mass 0.3 kg is taken up an inclined plane of length 10 m and height 5 m and then allowed to slide down to the bottom again. Coefficient of friction between the body and the plane is 0.15. What is the Work done by the gravitational force over the round trip?

Figure-2.47 shows a cylindrical container of radius 5cm and a piston is fitted in it to enclose a length of 20 cm in it.The cylinder contains an ideal gas at a pressure of 1 atmosphere and 300 K temperature.The cylinder is slowly heated and it is found that the piston starts displacing when the gas temperature reaches 600 K. It is given that the friction coefficient between the piston sidesand the container wall is 0.2. Find the normal force acting between piston sides and the container wall per unit length ofits circumference.

A body of mass 0.3kg is taken up an inclined plane of length 10m and height 5m, and then allowed to slide down to the bottom again. The coefficient of friction between the body and the plane is 0.15 . What is the (a) work done by the gravitational force over the round trip ? (b) work done by the applied force on the upward journey ? (c) work done by the frictional force over the round trip , (d)kinetic energy of the body at the end of the trip ?

A body of mass 0.3kg is taken up an inclined plane of length 10m and height 5m, and then allowed to slide down to the bottom again. The coefficient of friction between the body and the plane is 0.15 . What is the (a) work done by the gravitational force over the round trip. (b) work done by the applied force over the upward journey (c ) work done by frictional force over the round trip. (d) kinetic energy of the body at the end of the trip. How is the answer (d) related to the first three answers ? m=0.3kg , OA=10m , BA=5m