Centre of Gravity for Irregular Surfaces and Shift in Center of Gravity

Q.

How do you find the center of mass of an irregular object?

Q. The leaning tower of pisa does not fall. This is because the line of gravitational force ______ the base.

1. lies outside
2. passes through
3. is perpendicular to
4. is parallel to

Q. The centre of gravity of any freely suspended object lies directly ________ the point of suspension.

1. above
2. beneath
3. behind
4. beside

Q.

Which planets are smaller than earth?

Q.

Does the center of gravity of a body change when it is deformed?

Q.

How does Centre of gravity affect stability?

Q. The four major moons of the planet $\text{Jupiter}$ were discovered by:

1. $\text{Hans Lippershey}$
2. $\text{Galileo Galilei}$
3. $\text{Giovanni Cassini}$
4. $\text{Christian Huygens}$

Q.

Why does an object balance at its center of mass?

Q. Will $1$kg sugar be more at poles or at the equator?

Q. Why are the passengers in the upper deck of a double-decker bus not allowed to stand?

1. This ensures that the centre of gravity of the system may not rise up and the bus may not be toppled due to unstable equilibrium
2. This ensures smaller centripetal force, thus helping the driver to negotiate the roundabouts properly
3. If the passengers are in standing position, they may start oscillating due to jerks and there is a possibility of resonance, causing the bus to be toppled
4. This is just for the safety reason

Q. Karan is carrying a bucket containing 4 litres of water and Manu is carrying two buckets in which each bucket has 2 litres of water. Karan feels more difficulty. Why?

1. Its harder for Karan to balance the bucket.
2. Karan has less strength.
3. Karan has to push the bucket instead of pulling it.
4. Karan is carrying more weight.

Q. A person of mass 80kg is inside an elevator moving upwards against the gravity with an acceleration of 6m/s^2. Taking g = 10m/s^2, what is the net weight of the person?

Q. Body under influence of gravity is stable when the weight vector passes through the base of the body.

1. True
2. False

Q. Given that there is a relationship between the orbital radius of a planet and its period of revolution and that the periods of revolution of Mercury, Earth, Jupiter and Neptune and nearly 0.24, 1, 11.8 and 165 years. It follows that the period of revolution of
1. Venus is less than 0.24 years
2. Mars is less than 12 years
3. Uranus is more than 165 years
4. Uranus is less than 165 years but more than 12 years.

1. 1 and 3
2. 4 only
3. 3 o nly
4. 2 and 4

Q. What is the weight of the body at the centre of the earth ? With support your answer explain

Q. Why does a body lose weight at the centre of the earth?

Q. Identify the part of the scale, which if is the center of gravity, will cause the scale to fall from the table.

1. 
2. 
3. 

Q. State whether given statement is True or False.

1. True
2. False

Q. For a ball falling in a iiquid with constant velocity, ratio of resistance force due to the liquid to that due to gravity is

1. $\frac{2a^2\rho g}{9xv}$
2. $\frac{2a^2\rho g}{9{\eta }^2}$
3. $\frac{2a^2(\rho -\sigma )g}{9\eta }$
4. none of these

Q. A man is standing against a wall such that his right shoulder and right leg are in contact with the surface of the wall along his height. Can he raise his left leg at this position without moving his body away from the wall? Why? Explain.

Q. A hollow sphere is held suspended, sand is now poured in it.The centre of gravity of the sphere with the sand :

1. Rises continuously
2. Remains unchanged
3. First rises and then falls to original position
4. First falls and then rises to original position

Q. If the earth shrinks such that its mass does not change but radius decreases to one quarter of its original value then one complete day will take:

1. 48 h
2. 96 h
3. 6 h
4. 1.5 h

Q. Why flame is in always upward direction.

Q.

Define the terms mass

Q. The position of the centre of gravity of an object

1. affects its stability
2. can't predicted
3. is the middle point of the object
4. does not affect its stability.

Q. How can you find the center of gravity of an Indian map made of steel? Explain.

Q. If the line through the centre of gravity falls outside the base, then the object will be ___.

1. unstable
2. stable
3. partially stable
4. None of the above

Q. Explain some situations where the center of gravity of man lies out side the body.

Q. An object after deforming

1. doesn't change its centre of gravity
2. have same centre of mass
3. none of the above
4. may have different centre of mass.

Q. Which among the following is the major cause of nutation in Earth's axis:

1. Earth's Oblate spheroid shape
2. The difference between Land and Sea hemispheres
3. Oceanic Currents
4. TIdal Forces