Free vibration ofa system is vibration that occurs in the absence of external force. An external force that acts onthe system causes forced vibrations. In this case, the exciting force continuously supplies energyto the system. Forced vibrations may be either deterministic or random (see Fig.
Of course it's your name--I learned that in 8th grade. Now for one (the first) from 7th grade and one from college (the second). 1. What do you have when you sit down and lose every time you stand up? 2. What is it that men do standing up, but women are allowed to do while sitting down? (A warning: this is suitable for mixed company, but maybe not for mixed-up company.) This is about as close as I'd come to probable offenses on this site.
Do and does are used when we want to ask yes/no questions. We use do or does depending on the subject. Below are two sentences with two different subjects, she and you. Does she like sport? Yes, she does. Do you like sport? Yes, I do. Do. We use do when the subject is I, you, we or they. Do I know you? Do you come from England? Do we have to cut the grass? Do they want to come with us? Does. We use does with third person singular pronouns i.e when the subject is he, she or it. Does he work with you? Does she have a car? Does it snow in winter? Past Tense. Did is the past form of both do and does. Did he call you? Did you enjoy it? Negatives. The negative form of do is do not. In spoken English it is common to use the contracted form of do not which is don't. I do not like sport. I don't like sport. The negative form of does is does not. Also, in spoken English we usually use the contracted form of does not which is doesn't. He does not like sport.