6.A 1 kg object suspended by a thread is (i) lifted up with an acceleration of g / 2 (ii) lowered with an acceleration of g / 2. The ratio of the tensions in the two cases is

7.An open knife edge of mass M is dropped from a height h on a wooden floor. If the blade penetrates distance S into the wood, the average resistance offered by the wood to the blade is

8.Two masses 5 kg and 3 kg are suspended from the ends of an inextensible light string passing over a frictionless pulley. When the masses are released, the force exerted by the string on the pulley is

9.The ratio of the weight of a man in a stationary lift and in a lift accelerating downwards with a uniform acceleration a is 3 : 2. The acceleration of the lift is

10.A block of mass M is pulled along a horizontal frictionless surface by a rope of mass m. Force P is applied at one end of the rope. The force which the rope exerts on the block is