__Question 8.23__:^{30}kg).

__Solution__:Gravitational force,

*f*

_{g}= - GMm / R

^{2}

Where,

*M*= Mass of the star = 2.5 × 2 × 10

^{30}= 5 × 10

^{30 }kg

*m*= Mass of the body

*R =*Radius of the star = 12 km = 1.2 ×10

^{4}m

∴ f

_{g}= 6.67 X 10

^{-11}X 5 X 10

^{30}X m / (1.2 X 10

^{4})

^{2}= 2.31 X 10

^{11}m N

Centrifugal force,

*f*

_{c}

^{ }=

*mr*

*ω*

^{2}

*ω*= Angular speed = 2π

*ν*

ν = Angular frequency = 1.2 rev s

^{–1}

*f*

_{c}=

*mR*(2π

*ν*)

^{2}

=

*m*× (1.2 ×10

^{4}) × 4 × (3.14)

^{2}× (1.2)

^{2}= 1.7 ×10

^{5}

*m*

^{ }N

Since

*f*

_{g}>

*f*

_{c}, the body will remain stuck to the surface of the star.

## No comments:

## Post a Comment