A bird lands on a bird feeder which is connected to a spring. The mass of the bird is exactly the same as the mass of the bird feeder. How does the added mass affect the period of oscillation of the bird feeder?

The added mass will mean a longer period of oscillation.

Explanation:

The period of oscillation here is given by the formula;

T = 2π√(m/k)

Where m is mass and k is spring constant

From the equation of oscillation period above, it's obvious that when we increase the mass, the oscillation period will also increase.

Thus, the added mass will mean a longer period of oscillation.

the bal will not change its velocity.