Gravitation

Q.

Pressure depends on the ------- of force applied and the -------- of surface over which the force is applied.

1. magnitude
2. size
3. area
4. volume

Q. During ancient times, people believed that the Earth was the centre of the universe and all celestial bodies including the Sun revolved around the Earth. If this hypothesis were to be true, then:

1. Earth's mass should be proportionally much higher than the mass of Sun.
2. Sun's mass should be proportionally much higher than the mass of Earth.
3. Mass of Earth and Sun should be comparable.
4. The sum of masses of all celestial bodies should be comparable to that of the Earth

Q.

Calculate the magnitude of force required in newton to produce a pressure of 28500 Pa on an area of 100 cm².

Q.

A force of 200 N can produce a pressure of 20000 Pa. Calculate the area in cm² on which the force shall act to exert the pressure.

Q.

A force of 250 N, while acting on an area X produces a pressure of 1000 Pa. Calculate the magnitude of X in cm².

Q. Which of the following factors correctly determine the pressure of the fluid at a given point within the fluid ?

1. Depth
2. Density of fluid
3. Acceleration due to gravity
4. Shape of container

Q.

Suppose the gravitational attraction of earth suddenly disappears, then

1. weight of body becomes zero but mass remains unchanged

2. weight and mass of body both becomes zero

3. weight and mass of body both remains unchanged

4. weight of body remains unchanged but mass becomes zero of weight

Q.

A boy while playing under a mango tree saw a mango falling on his head. This is due to the force of:

1. magnetic force

2. can't be said

3. gravity

4. friction

Q. When the area of the edge of a knife is, the applied on object increases, thereby making the knife sharp and easy to use.

1. increased
2. force
3. pressure
4. decreased

Q.

Which of the following forces is responsible for the raindrops falling downwards?

1. Electrostatic force

2. Magnetic force

3. Gravitational force

4. Frictional force

Q. The pressure at a certain level in a water tank is

1. equal in all directions
2. unequal in all directions
3. infinitely large
4. always varying

Q.

The mass and weight of a body:

1. differ by a factor of 9.8

2. are identical

3. are both a direct measure of the inertia of the body

4. have the same ratio as that of another body placed at that location.

Q.

Pressure is defined as the _____________ acting per unit area of a body.

Q.

What is GRAVITY? How does GRAVITY work?

Q. What is the SI unit of relative density?

1. $gc{m}^{-3}$
2. $kg{m}^{-3}$
3. $gc{m}^3$
4. Unitless

Q.

Select the correct relation(s) for pressure.

1. Pressure is inversely proportional to force applied.

2. Pressure is directly proportional to force applied.

3. Pressure is inversely proportional to the area.

4. Pressure is directly proportional to the area.

Q. a force of 100 N act on a surface of area 25 cm calculate thrust and pressure. calculate the change pressure is the force now is reduce to 25 N ?

Q.

Two identical cubes A and B are placed in a tank containing a liquid as shown below. Choose the correct statement regarding pressures exerted on them.

1. The pressure experienced by cube A is more.

2. The pressure experienced by cubes A and B are equal.

3. We need to know density of the liquid to compare the pressures experienced by cubes A and B.

4. The pressure experienced by cube B is more.

Q.

It is known that falling apple is attracted towards the Earth. We all know that the apple will also exert an equal and opposite force on the Earth. If so, we don’t observe Earth moving towards the apple, why?

1. Both are applying equal and opposite force on each other so it gets cancelled out.

2. The acceleration produced by the fruit in Earth would be negligible.

3. The acceleration produced in the fruit in Earth would be very high.

4. No acceleration produced by the fruit in Earth.

Q.

Distinguish between Thrust and Pressure.

Q. What is the pressure due to a thrust of 800 N acting on an area of $2m^2$?

1. $400Pa$
2. $100Pa$
3. $200Pa$
4. $300Pa$

Q. Which of the following is not a correct use of the sea diving suit?

1. To maintain body temperature.
2. To resist external pressure.
3. To decrease the buoyant force.
4. To facilitate oxygen supply.

Q.

Express bar in terms of Pascal.

Q.

What is the area of cross-section of a body in m², when it exerts a force of 50 N and produces a pressure of 2000 Pa?

Q.

State the factors on which pressure depends.

Q. 1.what is the magnitude of force which exerts a pressure of 10 pa on an area of 5m.