Answer:
The set of frequencies of the electromagnetic Waves emitted by the atoms of an element is called emission spectrum.
D. used by the entire scientific community
B. more accurate system of measurement
Answer:
W = 3.1 N
Explanation:
moments about any convenient point will sum to zero.
I choose summing about the knife edge mark and will assume the ruler of weight W is of uniform construction.
I will assume the ruler weight makes a positive moment
W[55 - 50) - 0.040(9.8)[ 95 - 55] = 0
5W = 15.68
W = 3.136
I think its B or D, most likely D.
