A student’s backpack, full of textbooks, is hung from a spring scale attached to the ceiling of an elevator. When the elevator is accelerating downward at 3.8~\text{m/s}^23.8 m/s 2 , the scale reads 60 N. What is the mass of the backpack?

1 - wave length

2 - amplitude

3 - crest

4 - trough

explanation:

duh.

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

v=ir = 3x15 =45 v

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid