astronomy
posted by John .
1. The radius of the Sun is 7 X 10^5 kilometers. Use powers of ten to show that the Sun's radius is about 100 times the Earth's radius.
2. Given that an astronomical unit is 1.5 X 10^8 kilometers and a lightyear is about 10^13 kilometers, how many AU are in a lightyear?
1 x 10^13

1.5 x 10^8
equals
.667 X 10^5 or 6.67 X 10^4
More exact is 63,239.4913
So if the earth is 6.4 X 10^3 radius
and the sun is 7 X 10^5 just take 6.4 X 10^3 times 109 to get 7 X 10^5
Means the sun is 109 times bigger than earth.
Respond to this Question
Similar Questions

astronomy
Arcturus is about half as hot as the Sun but is about 100 times more luminous. What is its radius campared to the sun. 
astronomy
Arcturus is about half as hot as the Sun but is about 100 times more luminous. What is its radius campared to the sun. If Arcturus is half as hot, it radiates (1/2)^4 = 1/16 as much as the sun PER UNIT AREA. But since it radiates 100 … 
Astronomy
The average distance between the Earth and the Sun is called the astronomical unit (AU), which is about 150 million km (1.5 x 108 km). Jupiter is 780 million km from the sun. a) How far is Jupiter from the sun in astronomical units … 
Physics
Calculate the position of the center of mass of the following pairs of objects. Use a coordinate system where the origin is at the center of the more massive object. Give your answer not in meters but as a fraction of the radius as … 
Physics
Calculate the position of the center of mass of the following pairs of objects. Use acoordinate system where the origin is at the center of the more massive object. Give youranswer not in meters but as a fraction of the radius as requested. … 
Physics Please help!
Calculate the position of the center of mass of the following pairs of objects. Use acoordinate system where the origin is at the center of the more massive object. Give youranswer not in meters but as a fraction of the radius as requested. … 
physics
the energy received by the earth from the sun is 1400w/m2. Assuming that the sun is a black body radiator and the ratio of the radius of the earth's orbit to the sun's radius is 216. Calculate the surface temperature of the sun. Stefan … 
earth
The quantity of radiation received by earth from the sun is 1.4 kW / m2. Assuming that sun is an ideal radiator, calculate the surface temperature of the sun. The ratio of the radius of earth's orbit to the radius of the sun is 216. 
Physics
What is the orbital velocity of the Earth around the Sun, assuming the Earth takes a perfectly circular orbit around the Sun? 
Physics
Find the gravitational force acting on the Sun by the Earth. Given: Mass of the Sun = 1.99 * 1030 kg Mass of the Earth = 5.98 * 1024 kg Radius of the Sun = 6.96 * 108 m Radius of the Earth = 6.37 * 106 m Distance between the Sun and …