The weight of an object when calculated by multiplying with the pull of the gravity is dependent on the mass of the object and the value of g. The value of g is constant however is still dependent on the distance of the object from the center of the Earth. Thus, the answers are <em>mass and distance. </em>
a) earth acts as a lange magnetic. Therefore when a magnet is hanging freely, it points towards the magnetic poles (like a compass)
b) like poles repel and unlike poles attracts. We can conclude with repulsion that poles are same
c) In our everyday experience aluminum doesn't stick to magnets. (under normal circumstances aluminum isn't visibly magnetic)
I hope that the attachment helps you..
Send wave from your location to the object and wait until echo is back.
Measure the time taken.
If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return