Question 1 :
A particle falling down freely under the influence of gravity covers a distance of 20 m in 4 secs. Find its acceleration

Question 2 :
The unit of mass in SI system is ______ and the unit of weight in SI system is _______.

Question 4 :
Assertion: Heavier bodies fall with greater acceleration. Reason: Gravitational force is stronger on heavier bodies.

Question 5 :
When a body is taken from the earth to the moon: 

Question 7 :
Helium is preferred over hydrogen for filling balloons because it is 

Question 8 :
The weight of an object in air is $$25 N$$ and the weight of that object when submerged in water is $$20 N$$? What is the relative density of the object? 

Question 9 :
The upward force acting on the body immersed in a fluid is called :

Question 10 :
If M is the mass of the earth and R its radius, the ratio of the gravitational acceleration and the gravitational constant is given by:<br/>

Question 11 :
Gravitation on moon is $$\dfrac{1}{6} th$$of that on earth. Whena balloon filled with hydrogen is released on moonthen this.

Question 12 :
A steel wire is suspended vertically from a rigid support When loaded with a weight in air it expands by$$\displaystyle L_{a}$$ and when the weight is immersed completely in water the extension is reduced to$$\displaystyle L_{w}$$ Then relative density of the material of the weight is

Question 13 :
A ball is thrown vertically upwards. The acceleration due to gravity:

Question 16 :
The mass of a planet is 4 times while its radius is 8 times that of the earth. If the weight of an object is 640 N on earth, what will be its weight on the planet?<br>

Question 17 :
A particle falling under gravity describes $$80 ft$$ in a certain sec. How long does it take to describe next $$112 ft$$?$$[g=32fts^{-2}]$$

Question 18 :
The mass of the moon is 1% of mass of the earth.The ratio of gravitational pull of earth on moon to&#160;that of moon on earth will be:

Question 19 :
A capillary tube is immersed vertically in water and the height of the water column is x. When this arrangement is taken into a mine of depth $$d$$, the height of the water column is $$y$$. If $$R$$ is the radius of theearth, the ratio $$\dfrac {x}{y}$$ is :

Question 20 :
In a hypothetical case, if the diameter of the earth becomes half of its present value and its mass becomes four times of its present value, then how would the weight of any object on the surface of the earth be affected?<br>

Question 21 :
The maximum vertical distance through which a fully dressed astronaut can jump on the earth is&#160;0.5 m. If mean density of the moon is two thirds&#160;that of the earth and radius is one quarter that of the earth, the maximum vertical distance through&#160;which he can jump on the moon and the ratio of&#160;time of duration of the jump on the moon to that&#160;on the earth are.

Question 22 :
Consider two solid uniform spherical objects of the same density $$\rho$$. One has radius $$R$$ and the other has radius $$2R$$. They are in outer space where the gravitational fields from other objects are negligible. If they are arranged with their surface touching, what is the contact force between the objects due to their traditional attraction?<br>

Question 23 :
If R is the radius of a planet, g is the acceleration due to gravity then find the mean density of the planet

Question 24 :
An extremely small and dense neutron star of mass $$M$$ and radius $$R$$ is rotating at an angular frequency $$\omega$$. If an object is placed at its equator, it will remain stuck to it due to gravity if

Question 25 :
If the diameter of earth becomes two times its present value and its mass remains unchanged then how would the weight of an object on the surface of the earth be affected?