Question
What do you mean by gravitational constant? State its SI units.
✓
Answer
From Newton’s law of gravitation,
$F=G \frac{m_1 m_2}{r^2}$
where, G = constant called universal gravitational constant Its value is $667 X 10^{-11} N m^2/kg^2$.
$G=\frac{F_r^2}{ m _1 m _2}$
If $m_1=m_2=1 kg , r=1 m$ then $F=G$.
$F=G \frac{m_1 m_2}{r^2}$
where, G = constant called universal gravitational constant Its value is $667 X 10^{-11} N m^2/kg^2$.
$G=\frac{F_r^2}{ m _1 m _2}$
If $m_1=m_2=1 kg , r=1 m$ then $F=G$.
- Hence, the universal gravitational constant is the force of gravitation between two particles of unit mass separated by unit distance.
- Unit: $N m^2/kg^2$ in SI system.
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