What is it about these minerals (iron, nickel and magnetite) that make the Earth one big magnet?

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

In order for the bug to fly through the air a force has to push the bug forward. identify this force. how does the bug produce

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.