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

Answer 1

Answer: (B)

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

Answer 2

$a={{\omega }^{2}}r=4{{\pi }^{2}}{{v}^{2}}r$ $=4\times {{\pi }^{2}}\times {{1}^{2}}\times 20\times {{10}^{3}}$ $\therefore$ $a=8\times {{10}^{5}}m/{{s}^{2}}$