Alternating current (AC) flows half the time in one direction and half the time in the other, changing its polarity 120 times per second with 60-hertz current.
Answer:
a) La aceleración angular es: 
b) El engranaje gira 125 radianes.
c) El engranaje hara aproximadamente 20 revoluciones.
Explanation:
a)
La aceleración angular se define como:

Donde:
- Δω es la diferencia de velocidad angular (en otras palabras ω(final)-ω(inicial))
- Δt es el tiempo en el que occure el cambio de velocidad angular


b)
El desplazamiento angular puede ser calculado usando la siguiente ecuación:

Aqui el angulo inicial es 0, por lo tanto.


El engranaje gira 125 radianes.
c)
Lo que debemos hacer aquí es convertir radianes a revoluciones.
Recordemos que 2π rad = 1 rev
Entonces:

Por lo tanto el engranaje hara aproximadamente 20 revoluciones.
Espero te haya sido de ayuda!
Frequency is the vibration of noise and the vibration determines the pitch, which we depend on to be a pitch or frequency we can hear. If it's too high or too low our ears can't hear it
Answer:
True
Explanation:
With the increase in temperature hypothalamus fails and heatstroke occurs due to this failure. Hypothalamus is the region of our brain that act as a thermostat. It co-ordinates our physiological response to excessive heat. When the person’s temperature reaches to 104 degrees then it causes heatstroke. This heatstroke is very sudden and can kill person. Hence, we can conclude that when person’s temperature reaches to 104 degrees chances of survival decreases dramatically.