The mass m of the object = 5.25 kg
<h3>Further explanation</h3>
Given
k = spring constant = 3.5 N/cm
Δx= 30 cm - 15 cm = 15 cm
Required
the mass m
Solution
F=m.g
Hooke's Law
F = k.Δx

Why is it important that your finger be wet if you intend to touch it briefly to a hot clothes iron to test its temperature. If your finger is wet, some of the heat transmitted to your finger will be given to the water which has a high specific heat capacity and also a larger latent heat of vaporization.
#carryonlearning
Answer:
Phenomenon
Explanation:
phe·nom·e·non
/fəˈnäməˌnän/
noun
1.
a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question:
"glaciers are unique and interesting natural phenomena"
synonyms
occurrence, event, happening, fact, situation, etc.
2.
a remarkable person, thing, or event:
"the band was a pop phenomenon just for their sales figures alone"
synonyms
marvel, sensation, wonder, prodigy, miracle, etc.
We know, Period = 1/frequency = 1/20 sec.
So, your final answer is 0.05 sec
Hope this helps!