the frequency =100 HZ, find the the time between first crest and forth trough

Question

how to get the time from this given 

 

my answer is  f=100      p.t= 1/100

 

t=0.01 sec is that right?

Answer 1

Hey Ako -- at 100 Hz, one cycle is 0.01s or 10ms ... 1st peak to 2nd peak => 10ms ... 

 

to 3rd peak => 20ms ... to 4th peak => 30ms ... to next trough, add 1/2 cycle => 35ms :)

 

 

Answer 2

Hi Aka;

IF YOU ALREADY READ THIS, I MADE ONE CORRECTION.

100 Hz

(100 cycles)/(1 second)

(1 second)/(100 cycles)

We need the time between...

First crest and second crest...first cycle

second crest and third crest...second cycle

third crest and fourth crest...third cycle

fourth crest and fourth trough...half cycle

[(1 second)/(100 cycles)](3.5 cycles)

The unit of cycles is in the numerator and denominator.  It cancels...

[(1 second)/(100 cycles)](3.5 cycles)

[(1 second)/100](3.5)

[(3.5)/(100)]seconds

0.035 seconds