Suppose the mass is pulled down to where the spring's length is 72 cm . when it is released, it begins to oscillate. what is the amplitude of the oscillation?

The question is incomplete. This is the complete question: A spring has an unstretched length of 22 cm. A 150 g mass hanging from the spring stretches it to an equilibrium length of 30 cm. Suppose the mass is pulled down to where the spring's length is 38 cm. When it is released, it begins to oscillate. What is the amplitude of the oscillation?

The amplitude of the oscillation is 8 cm.

Explanation:

The amplitude of the oscillation, which is the maximum displacement of the stretched spring from equilibrium or rest, can be calculated by subtracting the spring’s length at equilibrium (when being stretched by 150g mass) from the spring’s length when it was pulled down.

Amplitude = A = the spring’s length when it was pulled down before oscillating (i.e., 38cm) — the spring’s length at equilibrium (i.e., 30cm)

Therefore, A = 38cm — 30cm = 8cm.

c) up is the direction the magnetic force is acting on the charge.