Question

6. Neptune orbits the Sun in 164.5 Earth yearsin an approximately circular orbit at a radius of 4.5 × 109 km, mil (a) Determine the orbital speed of Neptune.us to (h) Determine the mass of the Sun.) 。 .30

Answer 1

Radius of orbit R = 4.5 times 10^9 km = 4.5 times 10^12 m Time period of revolution T = 164.5 years earth T = 164.5 times (365.5) times 24 times 3600s T = 5191225200s oral orbital velocity U = circumference/Time period = 2 pi R/T U = 2 times pi times 4.5 times 10^12 m/5191225200s = 5.45 times 10^3 m/s \r\n part b In planetary motion, orbital speed U = ssqr G M_planet/R In our case, U = squareroot G M_sun/R M_sun = V^2 times R/G Putting Values M_sun = (5.45 times 10^3 m/s)^2 times 4.5 times 10^12 m/6.67 times 10^-11 N m^2/kg^2 M_sun = 2.00 times 10^30 kg