Question

A star 2.5 times the mass of the sun and collapsed to a size of 12 km rotates with a speed of 1.5 rev/s. An object placed on its equator will (mass of the sun =2 x 10³⁰ kg)

(a) remain stuck to its surface

(b) leave is surface

(c) move towards sun

(d) remain/leave depending on object’s mass

Answer 1

Correct option is (a) remain stuck to its surface

M = 2.5.x Mass of the sun

= 2.5 x 2 x 10³⁰ kg

R = 12 km = 12 x 10³ m

Acceleration due to gravity on star’s surface

As g > a_c, so object will remain stuck to star’s surface.