Final answer:
When the initial stretch is 5 cm, it will also take 4 seconds for one complete oscillation. When the mass is doubled, the period of the system will be the same as before, multiplied by a factor of square root of 2.
Step-by-step explanation:
To find the time for one complete oscillation when the initial stretch is 5 cm, we can use the equation for the period of a mass-spring system:
Period = 2π√(m/k)
Where m is the mass and k is the spring constant. Since the spring constant remains the same, the equation becomes:
Period = 2π√(m)
Since the mass does not change, the period remains the same.
Therefore, when the initial stretch is 5 cm, it will also take 4 seconds for one complete oscillation.
When the mass is doubled, the equation for the period becomes:
Period = 2π√(2m)
Therefore, the period of the system will be the same as before, multiplied by a factor of √2.