Question:
Fill in the blanks :
All other variables remaining constant, the force of gravitation is ________ proportional to the square of distance between the two objects.
Gravitation
Q 1.
State Kepler’s Laws of planetary motion. How did Newton guess inverse square law ?
Q 2.
A particle is dropped from a tower 180 m high.How long does it take to reach the ground ? What is the velocity when it touches the ground ? Take g =
Q 3.
Calculate the value of acceleration due to gravity on Moon. Given mass of Moon =
kg, radius of Moon = 1740 km
Q 4.
Why do sewing needles and all pins have a sharp pointed tip?
Q 5.
What is the value of ‘g’ at the centre of Earth ?
Q 6.
A boy on a clif£ 49 m high drops a stone.One second later,he throws a second stone after the first.They both hit the ground at the same time. With what speed did he throw the second stone ?
Q 7.
Which force is responsible for tides in the ocean at night ?
Q 8.
Two stones A and B are dropped from a multistoried building. A is dropped from 100 m and after some time B is dropped from 50 m height. Both of them reach the earth at the same time. Will they have equal velocity while reaching the ground ? Calculate and find out the answer (take g =10 m/s
2).
Q 9.
Fill in the blanks :
Every object in the universe ________ other bodies.
Q 10.
Can you calculate density of Earth from Newton’s law of gravitation ?
Q 11.
The mass of Earth is
kg and that of moon is
kg. If the distance between the Earth and the Moon is
km, calculate the force exerted by Earth on the Moon. Given G =
.
Q 12.
Suppose a planet exists whose mass and radius both,are half those of Earth.Calculate the acceleration due to gravity on the surface of this planet.
Q 13.
What do you mean by acceleration due to gravity ?
Q 14.
At what height above the surface of the earth, the value of 'g' becomes 64% of its value at the surface of the earth. Take radius of the earth = 6400 km.
Q 15.
What do we call the gravitational force between the Earth and an object ?
Q 16.
Who measured the value of G first time, experimentally?
Q 17.
Fill in the blanks :
________ of an object is the force of gravity acting on it.
Q 18.
What is the importance of universal law of gravitation ?
Q 19.
What is value of ‘g’ on Earth ?
Q 20.
A body is projected upwards. What is its velocity at maximum height
Q 21.
State and explain universal law of gravitation given by Newton.What is the importance of this law
Q 22.
Distinguish between mass and weight.
Q 23.
Why will a sheet of paper fall slower than one that is crumpled into a ball?
Q 24.
Calculate the force of gravitation between two objects of masses 80 kg and 1200 kg kept at a distance of 10 m from eachother.Given, G =
/
.
Q 25.
Mass of an object is 10 kg. What is its weight on the Earth? (g = 9.8 m/s
2.)
Q 26.
What are Plimsoll Lines?
Q 27.
A stone drops from the edge of the roof.It passes a window 2 m high in 0.1 s.How far is the roof above the top of the window
Q 28.
An object is thrown vertically upwards and rises to a height of 10 m. Calculate (i) the velocity with which the object was thrown upwards and (ii) the time taken by the object to reach the highest point.
Q 29.
A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet
Q 30.
Then why Is the Earth not seen moving towards the stone ?
Q 31.
Can a body have mass but no weight ?
Q 32.
Fill in the blanks :
The value of
g ________ (increases/decreases) as we go downwards from the earth's surface.
Q 33.
Fill in the blanks :
The value of G was found out by _______ by using a ________.
Q 34.
What is the gravitational force between the Earth and a body called? In which direction does it occur?
Q 35.
An object moves in a circular motion due to centripetal force, acting towards the center. The moon also rotates around the earth? Does centripetal force acts on it? Why does the moon not fall on the earth?
OR
Q:If the moon attracts the earth, why does the earth not move towards the moon?
Q 36.
Define 'g' or acceleration due to gravity? Does it depend on the mass of the body (near the surface of the earth)experiencing 'g'?
Q 37.
Write the standard equations in the form when an object is dropped from a height?
Q 38.
Is weight a scalar quantity?
Q 39.
What do you mean by Thrust or Buoyant force?
Q 40.
Relative density of silver is 10.8. If the density of water is 10
3kg/m
3, find density of silver.
Q 41.
Two bodies A and B having masses 2 kg and 4 kg respectively are separated by 2 m.Where should a body of mass 1 kg be placed so that the gravitational force on this body due to bodies A and B is zero ?
Q 42.
A force of 20 N acts upon a body whose weight is 9.8 N.What is the mass of the body and how much is its acceleration ?
Q 43.
State the universal law of gravitation.
Q 44.
Write the formula to find the magnitude of the gravitational force between the Earth and an object on the surface of the Earth.
Q 45.
Why is the weight of an object on the Moon (l/6)th its weight on the Earth ?
Q 46.
How does the force of gravitation between two objects change when the distance between them is reduced to half ?
Q 47.
Gravitational force acts on all objects in proportion to their masses.Why then,a heavy object does not fall faster than a light object ?
Q 48.
What is the magnitude of the gravitational force between the Earth and a 1 kg on its surface ? (Mass of the Earth Is
kg and radius of the Earth is
m.)
Q 49.
A stone is thrown vertically upward with an initial velocity of 40 m/s.Taking g =
,find the maximum height reached by the stone.What is the net displacement and the total distance covered by the stone ?
Q 50.
What is the value of G (i) on Earth (ii) on Moon ?
