Recent content by Tulio Cesar

The sound intensity formula is given by: dE/dT*dS. So the variables are energy, related to the amplitude of the wave, area, related to wavefronts distribution on space, and time. So many times I don't see any reference about the relation between frequency and sound intensity, but if time is a...

My question is: according to Carnot cycle, the maximum efficiency of a heat engine is given by 1 - T2/T1, where T2 is the temperature of the cold source and T1 the temperature of the hot source. So, accordingly, as higher T2 is for a same T1, lowest is the efficiency of the engine. But, the...

1) I am studying modulation of carrier waves, but I still can't understand something: knowing that in AM the carrier wave has only one frequency and just only its amplitudes vary according to variations in modulating signal amplitudes, why AM carrier waves have bandwidth if the frequency is...

1) I understood how variations in the amplitude of modulating signals are represented in the carrier wave, but I didn't get how frequency variations of the modulating signal are represented, as both AM and FM modulations seem do not care about it. Ex: How to distinguish a high vocal range (high...