Question

Calculate, using Newton's law of gravity, the size of the force of attraction between the earth and a mass of 2.0 kg on the earth. Data: Distance to the center of earth from the surface = 6370 km. Mass of earth = 5.98·1024kg. Gravitational constant G = 6.67·10-11 Nm2/kg2.

Calculate, using Newton's law of gravity, the size of the force of attraction between the moon and a mass of 2.0 kg on the earth's surface nearest the moon. Data: Distance to the moon from surface of the earth = 376,000 km. Mass of moon = 7.36·1022 kg.

Calculate, using Newton's law of gravity, the ratio of the strength of the force of attraction of a mass of 2.0 kg on the earth's surface by the sun to that by the moon. Additional Data: Mass of sun =1.99·1030 kg Distance from the sun to the surface of earth = 1.50·108 km.

Answer 1

the force of attraction due to gravitational force is given by the above terms

hence

F_{earth ball} = G* (M_earth * M_ball ) / distance² = 6.67 x 10^-11 * ((5.98x10²⁴ x 2)/( 6370 x10³) ) = 19.659 N

2) F_{moon ball} = G* (M_moon * M_ball ) / distance² = 6.67 x 10^-11 * ((7.36x10²² x 2)/( 376000 x10³) )= 6.944x10^-5 N

3) F_{sun ball :}F_{moon ball=} G* (M_sun * M_ball ) / distance_sun-ball² :G* (M_moon* M_ball ) / distance_moon-ball² =

= (M_sun *distance_moon-ball²) / (M_moon *distance_sun-ball²) = 169.89