Why are units of measurement useful?
a.
to complete the si system
b.
to make comparing amounts easier
c.
to allow scientists to do experiments
d.
to design better tools such as stopwatches

a

Explanation:

because the si system does not need to be completed. also the metric system can also.be used

the length that would produce a sound tone under the same experimental contditions must be increased by  Δl =

Explanation:

Recall

V = f ×λ

where λ is ⁴/₃l₂ for second resonance

f =

l₂ =

where λ is 4l₁ for 1st resonance

f =

l₁ =

∴ Δl = l₂ - l₁ =   ⁻  

Δl=  

Δl =

Therefore, the length should increase by