Answer:
Astronomers use a method similar to the one you used with your homemade quadrant. Twice the distance to the Sun, divided by the distance to the star (which is unknown so far) is equal to the tangent of the parallax angle of the star.
Geologist is the name of a scientist who studies rocks
To find out the weight of the object, you'll need to slide the weight poises until the pointer is at zero again. Start with the two heavier weight poises and then use the lightest one to do the fine tuning. Our triple beam balance and the Ohaus triple beam balance are accurate to 0.1 grams.
C. a lot of inertia.............................. :-)