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

Answer:
Properties of semiconductors are determined by the energy gap between valence and conduction bands. To understand, what is semiconductor, we have to define these terms. In solid-state physics, the energy gap or the band gap is an energy range between valence band and conduction band where electron states are forbidden.
Yo sup??
Average velocity=total distance covered/total time taken
total distance covered=4 + 8=12 miles
total time taken=6 hours
Therefore
average velocity=12/6
=2 miles/hour
Hope this helps
Option 2 is your answer :)