Question

What is the numerical value of gravitational constant?

• A. 10 $m{s}^{-2}$
• B. $6.67\times {10}^{-11}$ $N{m}^{2}k{g}^{-2}$
• C. 9.8 $m{s}^{-2}$
• D. $6.67\times {10}^{-11}$$N{m}^{2}K{g}^{-3}$

Answer 1

The correct option is B

$6.67\times {10}^{-11}$ $N{m}^{2}k{g}^{-2}$

The value of universal constant 'G' is an experimental value given by Henry Cavendish. It is a very low number, equal to $6.67\times {10}^{-11}$ $N{m}^{2}k{g}^{-2}$.
If two masses of 1 kg are separated at a distance of 1 m. Then the gravitational force acting between them will be very small i.e., $6.67\times {10}^{-11}$ N ($\frac{GMm}{r^2}$). Acceleration of 1 kg mass due to the force is $6.67\times {10}^{-11}$ $m{s}^{-2}$. The small acceleration has a negligible effect on the motion of the 1 kg mass.