How many calories of heat make up 1 calorie?

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

Two rigid transformations are used to map δhjk to δlmn. the first is a translation of vertex h to vertex l. what is the second transformation? a reflection across the line containing hk a rotation about point h a reflection across the line containing hj a rotation about point k

Need this now! do pilots live long