Aballoon is expanded to the same volume as that of a human head. do an order-of-magnitude estimate of the volume of this balloon in cm^3 a. 100cm^3 b. 1,000,000cm^3 c. 10cm^3 d. 1,000cm^3

20) what is a magnetic field? 21) in which direction do magnetic field lines always point? 22) sketch a diagram showing how a plotting compass points around a 23) name two magnetic poles that will: a) attract each other b) repel each other. 24) explain why you can use a compass to navigate. 25) what's an electromagnet? 26) list two ways to increase the strength of an electromagnet. 27) the wire in a simple motor feels a force when a current flows through it. why is this? i need answers to check mine