16. Two bodies of masses 15 kg and 5 kg are connected to the ends of a mass less cord and allowed to move as shown in figure. The pulley is massless and friction less. Calculate the acceleration of the centre of mass (g = 10 m/s): 15 kg 5 kg 5 3 m/s (1) 5 m/s (2) 7 m/s (3) { m/s (4) 1 17. Two car of mass m and m are moving in circles 1 radii r and r2. Their speeds are such that they make complete circles in the same time t the ratio of their centeripetal acceleration: 18. (1) 1:1 (3) m m (2) mr: mr2 (4) 11:12 A string breaks if its tension exceeds 10 newtons. A stone of mass 250 gm tied to this string of length 10 cm is rotated in a horizontal circle. The maximum angular velocity of rotation can be (1) 20 rad/s (3) 100 rad/s (2) 40 rad/s (4) 200 rad/s 19. Angular velocity of minute hand of a clock is: (1) rad/s 30 (2) rad/s (3) 2 rad/s (4) 1800 -rad/s