We know that centripetal acceleration is nothing but the ratio of the square of the tangential velocity to that of the radius vector.
a=v*v/r=ωωrr/r
=ωωr
=2πf2πfr
=2π2πr/TT
=97m/secsec
Mass does not change anywhere in the space .
So the given 30N is equal to the product of mass of the body and the acceleration due to gravity at that place in space.
After finding the mass of the body multiply it by the given acceleration due to gravity.
Mg is the approximate force due to gravity between the mass and the planet.
I hope this may help you.
Answer:
perihelion
Explanation:
The point at which a planet is closest to the sun is called perihelion. The farthest point is called aphelion
(a) 
The frequency of an electromagnetic wave is given by:

where
is the speed of the wave in a vacuum (speed of light)
is the wavelength
In this problem, we have laser light with wavelength
. Substituting into the formula, we find its frequency:

(b) 427.6 nm
The wavelength of an electromagnetic wave in a medium is given by:

where
is the original wavelength in a vacuum (approximately equal to that in air)
is the index of refraction of the medium
In this problem, we have

n = 1.48 (index of refraction of glass)
Substituting into the formula,

(c) 
The speed of an electromagnetic wave in a medium is

where c is the speed of light in a vacuum and n is the refractive index of the medium.
Since in this problem n=1.48, we find

Answer:
Explanation:
The correct answer is right