What is freud's term for the primitive, biological side of personality?

What are similarities and differences of reflection, refraction, diffraction and absorption?

Aclarinetist, setting out for a performance, grabs his 3.350 kg clarinet case (including the clarinet) from the top of the piano and carries it through the air with an upward force of 24.65 n. find the case's vertical acceleration. indicate an upward acceleration as positive and a downward one as negative.

What are the necessary conditions for fusion?