How can you tell if an igneous rock has an intrusive or extrusive origin?

Intrusive igneous rocks cool down from magma slowly because they form underneath the surface, that will make them have large crystals.

Extrusive igneous rocks cool down from lava rapidly because they form at the surface, so that will make them have small crystals.

gans

explanation:

vestigial organs (like your appendix) are organs that no longer serve a purpose.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.