A ball-bearing falling in a tall jar of motor oil attains a constant velocity. Explain the reason.

A ball falls under gravity from a height of 10m with an initial velocity. It collides with the ground,loses 50% of its engery and then rises to the same height.Find the initial velocity.

The magnitude of drift velocity of free electrons in a conductor is very low, but an electric bulb glows instantly when the current is switched on. Explain the reason.

Give the magnitude and direction of the net force acting onfa) a drop of rain falling down with a constant speed. (b) a cork of mass 10 g floating on water. (c) a kite skillfully held stationary in the sky. (cf) a car moving with a constant velocity of 30 km/h on a rough road.

A ball of mass m moving with a constant velocity strikes against a ball of same mass at rest.If e is the co-efficient if restitution what will be the ratio of velocity of two balls after collision?

The terminal velocity of a copper ball of radius 2.0 mm falling through a tank of oil at 20^@C is 6.5 cm/s. Compute the viscosity of the oil at 20^@C . Given, rho_(oil) = 1.5 xx 10^3 kg//m^3, rho_(copper) = 8.9 xx 10^3 kg//m^3 .

The velocity of falling rain drops attain limited veloity because of

A sphere of radius 0.25mm and of density 9000kg/m^3 falls through an oil of co-efficient of viscosity 0.2 Ns/m^2 and of density 800kg/m^3 . Find the terminal velocity of the sphere.

The ternimal velocity of small sized spherical ball of radius r falling vertically in a viscous liquid is

Using Stokes' Law show that the constant terminal velocity v of a sphere of radius r, density rho falling vertically under gravity through a viscous fluid of density sigma and co-efficient of viscosity eta is given by- v = (2/9).[{r^2g(rho - sigma)}/eta]