A closed tank containing water is moving in a horizontal direction along a straight line at a constant speed. The tank also contains a steel ball and a bubble of air. If the tank is decelerated horizontally, then
i) the ball will move to the front
ii) the bubble will move to the front
iii) the ball will move to the rear
iv) the bubble will move to the rear
Find out which of the above statements are correct ?

In a two dimensional incompressible steady flow around an airfoil, the stream lines are 2 cm apart at a great distance from the airfoil, where the velocity is 30 m/sec. The velocity near the airfoil, where the stream lines are 1.5 cm apart, is

A. 22.5 m/sec.

B. 33 m/sec.

C. 40 m/sec.

D. 90 m/sec.

According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to

A. the weight of the body

B. more than the weight of the body

C. less than the weight of the body

D. weight of the fluid displaced by the body

The difference of pressure between the inside and outside of a liquid drop is

A. $${\text{p}} = {\text{T}} \times {\text{r}}$$

B. $${\text{p}} = \frac{{\text{T}}}{{\text{r}}}$$

C. $${\text{p}} = \frac{{\text{T}}}{{2{\text{r}}}}$$

D. $${\text{p}} = \frac{{2{\text{T}}}}{{\text{r}}}$$

Fluid is a substance that

A. cannot be subjected to shear forces

B. always expands until it fills any container

C. has the same shear stress.at a point regardless of its motion

D. cannot remain at rest under action of any shear force