Question

If in a system the force of attraction between two point masses of $1kg$ each situated $1km$ apart is taken as a unit force and is called notwen (newton written in reverse order). If $G=6.67\times 10^{11}N-m^{2}k{g}^{-2}$ in $SI$ units, the relation of newton and notwen is:

• A. 1 notwen $=6.67\times 10^{11}$ newton
• B. 1 newton $=6.67\times 10^{17}$ newton
• C. 1 netwen $=6.67\times 10^{-17}$ newton
• D. 1 newton $=6.67\times 10^{12}$ newton

Answer 1

Answer: (C)

If two point masses each of masses $1kg$ are separated a distance $1m$ they experience a force $6.67\times 10^{11}$ newtons.

We know $F=G\frac{m_1{m}_2}{r^2}$

$1$ notwen $=6.67\times 10^{-11}\times \frac{{\left(1kg\right)}^2}{{\left(1km\right)}^2}$

$=6.67\times 10^{-11}\times 10^{-6}\frac{{\left(1kg\right)}^2}{{\left(1m\right)}^2}$

$=6.67\times 10^{-11}\times 10^{-6}$ newtons

1 notwen $=6.67\times 10^{-17}$ newtons