Question

Certain neutron stars are believed to be rotating at about $1$rev/s. If such a star has a radius of $20$km, the acceleration of an object on the equator of the star will be.

• A. $20\times {10}^{8}m/s^2$
• B. $8\times {10}^{5}m/s^2$
• C. $120\times {10}^{5}m/s^2$
• D. $4\times {10}^{8}m/s^2$

Answer 1

The correct option is B $8\times {10}^{5}m/s^2$

It is known $a={\omega }^{2}r=4{\pi }^2{v}^{2}r$

putting values:

$a=4\times {\pi }^2\times 1^2\times 20\times {10}^3$

$a=8\times {10}^{5}m/s^2$