# y2a = [10e^(-2t) – 15e^(-3t)] u(t) mg : a| The expression given above for ???(t) is strictly wrong b

y2a = [10e^(-2t) – 15e^(-3t)] u(t) mg : a| The expression given above for ???(t) is strictly wrong because it lacks units of measure. That is, for instance, e-2t is strictl incomputable when t 30 seconds because one cannot raise e to the power of -60 seconds: an e-60 would have been fine, but e-60 seconds? Is that e-1 minute? So which is it: e-60 or e-1? (Answer: neither.) For convenience and to reduce clutter, ECE 3704 usually omits the units of measure but an engineer should know how to reintroduce the units where greater precision of expression is required. For this reason, rewrite the expression given above for y2a(t) Using correct units of measure you sure that seconds are the correct unit of measure? That is, are you sure that seconds were the unit of time the instructor had in mind when he composed problem 2? Why not milliseconds? Why not weeks? How can vou tell what the instructor had in mind? Answer: with the information given, strictly speaking, you cannot tell.) Briefly comment . [b] Are