A coin is put on a long play record.The player is started but, before the final speed of rotation is reached, the coin flies off. Explain why?

In the "before" part of Fig., car A (mass 1100 kg) is stopped at a traffic light when it is rear-ended by car B (mass 1400 kg). Both cars then slide with locked wheels until the frictional force from the slick road (with a low mu_k of 0.10) stops them, at distances d_A = 8.2 m and d_B = 6.1 m. What are the speeds of (a) car A and (b) car B at the start of the sliding, just after the collision? (c) Assuming that linear momentum is conserved during the collision, find the speed of car B just before the collision. (d) Explain why this assumption may be invalid.

A player X has a biased coin whose probability of showing heads is p and a player Y has a fair coin. They start playing a game with their own coins and play alternately. The player who throws a head first is a winner. If X starts the game, and the probability of winning the game by both the players is equal, then the value of 'p is :

A small coin is placed at a distance r from the centre of a gramophone record.The rotational speed of the record is gradually increased. If the coefficient of friction between the coin and the record is mu, the minimum angular frequency of the record for which the coin will fly off is given by :

A coin is placed on a gramophone record rotating at a speed of 45 rpm, it flies away when the rotational speed is 50 rpm. If two such coins are placed one over the other on the same record both of them will fly away when rotational speed is

A coin is placed on the horizontal surface of a rotation disc. The distance of the coin from the axis is 1 m and coefficient of friction is 0.5. If the disc starts from rest and is given an angular acceleration (1)/(sqrt(2)) rad / sec^(2) , the number of revolutions through which the disc turns before the coin slips is

Two thin rectangular sheets (0.20 m xx 0.40 m) are identical. In the first sheet the axis of rotation lies along the 0.20-m side, and in the second it lies along the 0.40-m side. The same torque is applied to each sheet. The first sheet, starting from rest, reaches its final angular velocity in 8.0 s. How long does it take for the second sheet, starting from rest, to reach the same angular velocity?

small block of mass 200 g is kept at the top of a frictioinless incline which is 10 m long and 3.2 m high. How much work was required a. to lift the block from the ground nd put it at thetop b. to side the block up the incline? What will be the speed of the block when it reaches the ground if, c. it falls off the incline and drops vertically on the ground d. it slides down the incline? Take g=10 m/s^2 .

Two trains start simultaneously from two stations Howrah and Bandra, respectively towards each other on the same track. The distance between the two stations is 560 km and the speed of trains are 30 and 40 km/h. Simultaneously with the trains, a sparrow sitting on the top of one of the train starts towards the other and reverses its direction on reaching the other train and so on. If the speed of sparrow is 80 km/h then the distance that the sparror flies before being crushed between the train is :