Mechanical Prop...

Assertion: A raindrop after falling through some height attains a constant velocity

Assertion: For the flow to be streamlined, value of critical velocity should be as low as possible
Reason: Once the actual velocity of flow of liquid becomes greater than the critical velocity, the flow becomes turbulent.

Assertion: An object falling through a viscous medium eventually attains terminal velocity
Reason: All the rain drops hit the surface of the earth with the same constant velocity

A drop of water of radius r is falling through the air of coefficient of viscosity $$\eta $$ with a constant velocity of v. The resultant force on the drop is:

Read the following statements and pick the correct choice
Statement A: With increase in temperature, viscosity of a gas increases and that of a liquid decreases.
Statement B: If the density of a small sphere is equal to the density of the liquid in which it is dropped, then the terminal velocity of the sphere will be zero.

A small ball is dropped in a viscous liquid. Its fall in the liquid is best described by the figure:

After terminal velocity is reached the acceleration of a body falling through a viscous fluid is :

When a metallic sphere is dropped in a long column of a liquid, the motion of the sphere is opposed by the viscous force of the liquid. If the apparent weight of the sphere equals to the retarding forces on it, the sphere moves down with a velocity called:

A ball is dropped into coaltar. Its velocity-time curve will be

The reading of a pressure meter attached with a closed water pipe is 3.5 x 10$$^{5}$$ N m$$^{-2}$$. On opening the valve of the pipe, the reading of pressure meter is reduced to 3 x 10$$^{5}$$ N m$$^{-2}$$. Calculate the speed of water flowing in the pipe.