Choose the correct definition of Universal law of gravitation:
A
Every object in the universe attracts every other object with a force which is proportional to the product of the distance between them and inversely proportional to their masses.
B
Every object in the Universe attracts every other object with a force which is inversely proportional to the square of the distance between them and proportional to the product of their masses.
✓
Every object in the universe attracts every other object with a force which is proportional to their masses and inversely proportional to the square of distance between them.
D
Optaion $A$ or $C$
Answer
Correct option: C.
Every object in the universe attracts every other object with a force which is proportional to their masses and inversely proportional to the square of distance between them.
Every object in the universe attracts every other object with a force which is proportional to their masses and inversely proportional to the square of distance between them.
The gravitational force of attraction between two objects is x. Keeping the masses of the objects unchanged, if the distance between the objects is halved, then the magnitude of gravitational force between them will become:
$G$ is symbol used for gravitational constant, it is a universal constant and independent from type, place, mass, density, volume everything. it is always constant.
A satellite is launched in a circular orbit of radius $R$. Another satellite is also launched in an orbit of radius $1.1R$. The period of the second satellite is larger than the first by approximately.
A
$7.5\%$
✓
$1.5\%$
C
$15\%$
D
$10\%$
Answer
Correct option: B.
$1.5\%$
$T=\frac{2 \pi R}{\sqrt{\frac{G M}{R}}}, T \propto R^{\frac{3}{2}}$
Radius of $2^{\text {nd }}$ satellite is $1 \%$ greater Hence time period is $1 \times \frac{3}{2}=1.5 \%$ larger
Gravitational force between two objects is $10\ N$. If masses of both objects are doubled without changing distance between them, then the gravitational force would become:
Four balls, $A, B, C$ and $D$ displace $10\ mL, 24\ mL, 15\ mL$ and $12\ mL$ of a liquid respectively, when immersed completely. The ball which will undergo the maximum apparent loss in weight will be:
Two particles are placed at some distance from each other. If, keeping the distance between them unchanged, the mass of each of the two particles is doubled, the value of gravitational force between them will become:
Does the force of gravitation exist between two astronauts in space:
✓
Yes, always
B
Never
C
Only under special circumstances
D
Only on a planet
Answer
Correct option: A.
Yes, always
(a) Yes, always Explaination : Yes, there will be gravitational force between the two astronauts in space because every object in universe, whether small or large, exerts a force on every other object.
The earth and the moon are attracted to each other by gravitational force. The earth attracts the moon with a force that is:
A
More than that exerted by the moon.
✓
Same as that exerted by the moon.
C
Less than that exerted by the moon.
D
Not related to that exerted by the moon.
Answer
Correct option: B.
Same as that exerted by the moon.
(b) Same as that exerted by the moon. Explaination : According to the universal law of gravitation, two objects with masses attract each other with equal gravitational force, but in opposite directions.
This force is given by
$
F=G \frac{M m}{r^2}
$
Hence, the earth attracts the moon with the same force with which the moon attracts the earth.