As mosquito is sitting on an L.P. record disc rotating on a trun tabel at `33 1/3` revolutions per minute. The distance of the mosquito from the centre of the turn table is 10 cm. Show that the frictioncoefficient between the record and the mosquito is greater than `pi^2/81`. Take `g=10m/s^2`

As mosquito is sitting on an L.P. record disc rotating on a turn table at 33 1/3 revolutions per minute. The distance of the mosquito from the center of the turn table is 10 cm. Show that the friction coefficient between the record and the mosquito is greater than pi^2/81 . Take g=10m/s^2

A disc rotates about its aixs of symmetry in a horizontal plane at a steady rate of 3.5 revolutions per second A coin placed at a distance fo 1.25 cm form the axis of ratation remains at rest on the disc The coefficient of friction between the coin and the disc is : (g=10//s^(2))

A disc rotates about its aixs of symmetry in a horizontal plane at a steady rate of 3.5 revolutions per second A coin placed at a distance fo 1.25 cm form the axis of ratation remains at rest on the disc The coefficient of friction between the coin and the disc is : (g=10//s^(2))

A circular disc is rotating about its own axis at the rate of 200 revolutions per minute. Two particles P,Q of disc are at distances 5cm,10cm from axis of rotation. The ratio of angular velocities of P and Q is

A gramophone disc is set revolving in a horizontal plane at the rate of 33(1)/(2) revolutions per minute. It is found that a small coin placed on the disc will remain there if its centre is not more than 5 cm from the axis of rotation. Calculate the coefficient of friction between the coin and the disc [Hint : Centripetal force = m omega^(2)r= Frictional force = mu N=mu mg ]

A boy is sitting on the horizontal platform of a joy wheel at a distance of 5 m from the center. The wheel begins to rotate and when angular speed exceeds 1 rad/s, the boy just slips. The coefficient of friction between the boy and the wheel is (g=10m//s^(2))

A boy is sitting on the horizontal platform of a joy wheel at a distance of 5 m from the center. The wheel begins to rotate and when angular speed exceeds 1 rad/s, the boy just slips. The coefficient of friction between the boy and the wheel is (g=10m//s^(2))

A gramophone disc of brass of diameter 30 cm rotates horizontally at the rate of 100//3 revolutions per minute. If the vertical component of the earth's magnetic field be 0.01" weber"//"metre"^(2) , then the emf induced between the centre and the rim of the disc will be-