Mar 17, 2006 #1 V v9260019 Member level 2 Joined Jun 5, 2005 Messages 47 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,286 Activity points 1,680 Hello all ^^ for the equation : y(t)=Exp(-at)u(t) we say that the " time constant " =1/a How to prove the " time constant " have the unit of s (second) thanks a lot
Hello all ^^ for the equation : y(t)=Exp(-at)u(t) we say that the " time constant " =1/a How to prove the " time constant " have the unit of s (second) thanks a lot
Mar 17, 2006 #2 VVV Advanced Member level 5 Joined Nov 26, 2004 Messages 1,575 Helped 384 Reputation 768 Reaction score 88 Trophy points 1,328 Activity points 19,971 Simply put, the exponent has to be dimensionless, therefore a*t is dimensionless, so 1/a must be measured in seconds.[/quote]
Simply put, the exponent has to be dimensionless, therefore a*t is dimensionless, so 1/a must be measured in seconds.[/quote]
Mar 23, 2006 #3 A Andrew8611 Member level 1 Joined Mar 16, 2006 Messages 37 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,288 Activity points 1,557 simple, you need that the exponent is adimensional, because u(t) and y(t) are in the same dimensions, so the only unit that can cancel t it's 1/t so a must have the unit 1/s.
simple, you need that the exponent is adimensional, because u(t) and y(t) are in the same dimensions, so the only unit that can cancel t it's 1/t so a must have the unit 1/s.