Respuesta :

480

This is this awnser because its 120 a second, for 4 seconds so 4 times 120 = 480.

Well the equation is rate*time=work/distance(in this case total vibrations)

Now we plug in the numbers:

(we know that 120 times per second is the rate because it uses the word per)

(4 seconds is the time because the unit is just seconds)

12*4=48*10=480

120*4=480

The answer is 480 vibrations

Hope this helps :)