physics
posted by jasmine .
in the model ,how far away from the earth would the sun be?

What model? I assume you are talking about some scale model of the solar system. You have to assign a value for the size one object in order to compute the sizes of others.
Then make the ratios of sizes in your scale model equal to tha actual values.
How large is the diameter of the sun in your model? That could be a place to start.