1. A spring experiences a simple harmonic movement, if it starts its movement when the spring is extended 20 cm. Calculate:

a) The elastic constant when applied 49.78N

b) If the spring weighs 3.45N, obtain its angular frequency.

c) Period

2. In a tide that presents the waves of the sea, it performs a simple harmonic movement and where the result obtained is a superposition of waves, where it states 15 cm above its equilibrium point, leading to a number of waves of 11π / 3 and 15π / 4 at a distance of 5.35m the superposition was made in a time of 7.9 sec. Calculate the resultant between the waves.

3. In the City of Florida, a space take-off training will be carried out, from which the intensity level at a point located at 1535 m is perceived as the "emitting noise" that is measured at 160 dB. Calculate:

a) The intensity of the sound at that distance. Consider Io = 1X10-12 W / m2

b) Power of the sound source.