Okhli vich sar dena da correct meaning te sentence bnao punjabi vich ess muhavre daa
Answers
Answer:
4
From equation (2), it can be seen that
the value of G is the gravitational force
acting between two unit masses kept at a
unit distance away from each other. Thus,
in SI units, the value of G is equal to the
gravitational force between two masses of
1 kg kept 1 m apart.
Show that in SI units, the unit of G
is Newton m2
kg-2. The value of G was
first experimentally measured by Henry
Cavendish. In SI units its value is
6.673 x 10-11 N m2
kg-2.
Use your brain power If the area ESF in figure 1.4 is equal to area ASB, what
will you infer about EF?
An introduction to scientists
Johannes Kepler (1571-1630) was a German astronomer
and mathematician. He started working as a helper to the famous
astronomer Tycho Brahe in Prague in 1600. After the sudden
death of Brahe in 1601, Kepler was appointed as the Royal
mathematician in his place. Kepler used the observations of
planetary positions made by Brahe to discover the laws of
planetary motion. He wrote several books. His work was later
used by Newton in postulating his law of gravitation.
1.5 Gravitational force between
two objects
Figure 1.5 shows two objects with masses m1 and
m2
kept at a distance d from each other. Mathematically,
the gravitational force of attraction between these two
bodies can be written as
m1
m2
d2 F a ....... (2)
m1
m2
d or F = G 2
Newton’s universal law of gravitation
All the above considerations including Kepler’s laws led Newton to formulate his
theory of Universal gravity. According to this theory, every object in the Universe attracts
every other object with a definite force. This force is directly proportional to the product
of the masses of the two objects and is inversely proportional to the square of the distance
between them.
Here, G is the constant of proportionality and is called the Universal gravitational
constant.
The above law means that if the mass of one object is doubled, the force between the
two objects also doubles. Also, if the distance is doubled, the force decreases by a factor
of 4. If the two bodies are spherical, the direction of the force is always along the line
joining the centres of the two bodies and the distance between the centres is taken to be d.
In case when the bodies are not spherical or have irregular shape, then the direction of
force is along the line joining their centres of mass and d is taken to be the distance
between