Thrust and Pressure

Q.

State two factors on which pressure at a point inside a liquid depends.

Q.

An astronaut has 80 kg mass on earth :

What will be his mass and weight on mars? [Take g of mars = $3.7m{s}^{-2}$]

Q.

Inverse square law means $\mathrm{F}\propto \frac{1}{{\mathrm{d}}^2}$.

1. True
2. False

Q. Which of the following is equivalent to 1 pascal?

1. $1N{cm}^{-2}$
2. $1N{m}^{-2}$
3. $1m{N}^{-2}$
4. $1cm{N}^{-2}$

Q. The time periods of revolution of Earth and Jupiter are in the ratio 1:12. Then the radii of Jupiter and Earth are in the ratio .

1. $1:24\sqrt{3}$
2. $\sqrt[3]{3144}$$:1$
3. $24\sqrt{3}:1$
4. $1:$$\sqrt[3]{3144}$

Q.

The same force acting on a smaller area exerts a larger pressure and a smaller pressure on a larger area.

Q.

A tank which is $3m$long, $1m$wide, and $0.5m$deep is filled with oil that weighs $1200N$. What is the pressure on the base of the tank due to oil?

Q.

For a fix force pressure varies directly as the area of cross section of the surface.

1. True
2. False

Q. If there exists a gravitational force of $2\times {10}^{20}N$ between the Earth and the Moon, find the mass of Earth. ​Take mass of the moon as $7.4\times {10}^{22}kg$.

1. $3\times {10}^{24}kg$
2. $6\times {10}^{27}kg$
3. $6\times {10}^{34}kg$
4. $3\times {10}^{30}kg$

Q.

Deep-sea divers wear special suits.

Q.

Pressure at the bottom of sea at some particular place is 9, 00, 0000 Pa. If density of sea water is $1.0{\mathrm{gcm}}^{-3}$, then what is the depth of sea (Neglect the pressure of the atmosphere and take $\mathrm{g}=10{\mathrm{ms}}^{-2}$.

1. $865\mathrm{m}$

2. $8600\mathrm{km}$

3. $86000\mathrm{m}$

4. $8.6\times {10}^7\mathrm{m}$

Q.

A man weighs $600N$ on the equator, but when he moves to the pole he finds a slight increase in his weight. This is because:

1. Radius of the Earth is less at poles.

2. Radius of the Earth is more at poles.

3. The mass of the Earth increases at poles.

4. Newton's law of gravitation is not applicable at the poles.

Q. How much thrust (in $\text{N}$) will be required to exert a pressure of $20,000\text{Pa}$ on an area of $15{\text{cm}}^2$?

1. 30