Sabendo que a oscilação desta mola (quando se solta a esfera da posição B) possui um período de 2,5 s, calcule a frequência das suas oscilações e represente na figura o sentido da força restauradora.

0.4 Hz

Explanation:

For an object in simple harmonic motion, the relationship between frequency and period is:

where:

f is the frequency (the number of complete oscillations per second)

T is the period (the time it takes for the object to complete one oscillation)

In this problem, we have an object with a period of oscillation of

T = 2.5 s

Therefore, the frequency of oscillation is:

Here we also want to know the direction of the restoring force. A simple harmonic motion is a motion in which there is a restoring force proportional to the displacement:

where

k is the spring constant

x is the displacement

We notice in the formula that there is a negative sign: it means that the direction of the force is opposite to the displacement. Therefore, the force  always points towards the equilibrium position of the system.

i think the answer would be b