Question:
The tangential velocity of a planet or moon moving in a circle is at a right angle to ____________. (fill in the blank)
Answer:
the force of gravity
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.
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 12.
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 13.
What do you mean by acceleration due to gravity ?
Q 14.
What do we call the gravitational force between the Earth and an object ?
Q 15.
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 16.
What is the importance of universal law of gravitation ?
Q 17.
Who measured the value of G first time, experimentally?
Q 18.
Fill in the blanks :
________ of an object is the force of gravity acting on it.
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.
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 23.
Distinguish between mass and weight.
Q 24.
Mass of an object is 10 kg. What is its weight on the Earth? (g = 9.8 m/s
2.)
Q 25.
Why will a sheet of paper fall slower than one that is crumpled into a ball?
Q 26.
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 27.
Fill in the blanks :
Universal gravitational constant G = _____________.
Q 28.
What are Plimsoll Lines?
Q 29.
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 30.
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 31.
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 32.
Then why Is the Earth not seen moving towards the stone ?
Q 33.
Can a body have mass but no weight ?
Q 34.
Can a body have weight but no mass ?
Q 35.
On earth,value of G =
.What is its value on moon,where g is nearly
th that of earth ?
Q 36.
Fill in the blanks :
Kepler's Law of ______ states that a line that connects a planet to the Sun sweeps out equal ______ in the plane of the planet's orbit in _____time intervals.
Q 37.
Fill in the blanks :
The value of
g ________ (increases/decreases) as we go downwards from the earth's surface.
Q 38.
Fill in the blanks :
The value of G was found out by _______ by using a ________.
Q 39.
Why is G called the Universal Constant?
Q 40.
What is the gravitational force between the Earth and a body called? In which direction does it occur?
Q 41.
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 42.
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 43.
What are the differences between the mass of an object and its weight?
Q 44.
Write the standard equations in the form when an object is dropped from a height?
Q 45.
Is acceleration due to gravity a vector or a scalar? Write its S.I. unit.
Q 46.
Is weight a scalar quantity?
Q 47.
Why does one feel giddy while moving on a merry go round ?
Q 48.
What is weightlessness?
Q 49.
Fill in the blanks :
Motion of body with constant speed in a circular path is called ______________.
Q 50.
Fill in the blanks :
All other variables remaining constant, the force of gravitation is ________ proportional to the square of distance between the two objects.
