An air bubble of negligible weight having radius r rises steadily through a solution of density $$\sigma$$ at speed v. The coefficient of viscosity of the solution is given by :

A wire of length L is hanging from a fixed support. The length changes to L₁ and L₂ when masses 1 kg and 2 kg are suspended respectively from its free end. Then the value of L is equal to :

A block of metal weighing 2 kg is resting on a frictionless plane (as shown in figure). It is struck by a jet releasing water at a rate of 1 kgs^$$-$$1 and at a speed of 10 ms^$$-$$1. Then, the initial acceleration of the block, in ms^$$-$$2, will be :

A water drop of radius 1 $$\mu$$m falls in a situation where the effect of buoyant force is negligible. Co-efficient of viscosity of air is 1.8 $$\times$$ 10^$$-$$5 Nsm^$$-$$2 and its density is negligible as compared to that of water 10⁶ gm^$$-$$3. Terminal velocity of the water drop is :

(Take acceleration due to gravity = 10 ms^$$-$$2)