如图所示,在光滑的水平面上,一质量为m,半径为r,电阻为R的均匀金属环,以v0的初速度向一磁感应强度为B的有界匀强磁场滑去（磁场宽度d>2r）.圆环的一半进入磁场历时t秒,这时圆环上产生的焦

如图所示,在光滑的水平面上,一质量为m,半径为r,电阻为R的均匀金属环,以v0的初速度向一磁感应强度为B的有界匀强磁场滑去（磁场宽度d>2r）.圆环的一半进入磁场历时t秒,这时圆环上产生的焦
如图所示,在光滑的水平面上,一质量为m,半径为r,电阻为R的均匀金属环,以v0的初速度向一磁感应强度为B的有界匀强磁场滑去（磁场宽度d>2r）.圆环的一半进入磁场历时t秒,这时圆环上产生的焦耳热为Q,则t秒末圆环中感应电流的瞬时功率为（ ）

如图所示,在光滑的水平面上,一质量为m,半径为r,电阻为R的均匀金属环,以v0的初速度向一磁感应强度为B的有界匀强磁场滑去（磁场宽度d>2r）.圆环的一半进入磁场历时t秒,这时圆环上产生的焦
金属环进入磁场后 会切割磁感线 从而产生感应电动势 又因是金属环是完整回路所以 就会有感应电流 有电流就存在功率 此时瞬时功率就是瞬时电压与电流相乘 根据公式 Q=I^2RT 得 I = 又根据公式 E=U=BLV 所以就能得出U （这儿的L是指有效地磁通量变化部分 也就是在真正意义上切割磁感线产生电流的部分 所以L=R) 最后P=UI

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10 Important, Easy Dating Rules for Your Success
10 Important, Easy Dating Rules for Your Success
style="padding-left:15,ghd; padding-right:10">1) Leave the mobile phone off! Do n...

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10 Important, Easy Dating Rules for Your Success
10 Important, Easy Dating Rules for Your Success
style="padding-left:15,ghd; padding-right:10">1) Leave the mobile phone off! Do not answer it if it is on Silent either. You should only do this if you are expecting an emergency and I mean an emergency. You only look like a deadhead, self-centred fool answering a phone at a meeting that is important and that goes for all meetings. It's inconsiderate and breeds contempt from the other party even if they agree to you answering it. They're only being polite which you're not,CHI Flat Iron, if you do have a ringing phone and answer it. This does not mean leave it at home - you may need it later.2) Don't smoke anything in the presence of others unless they also smoke and for goodness sake make sure that no one near you is eating. Never smoke in an area where people are eating even if they smoke. You would be a fool to smoke in the presence of your date when they didn't smoke. If you're keen,ghd, it may be time to think about not smoking in their presence again.3) A good rule is not to talk about your achievements unless you are asked. Bragging is more often frowned upon and puts people off early. Show some interest in your date and their hobbies achievements and interests. If you do this regularly enough, it will become a habit and your good social skills will become very obvious to others including your date. 4) Find some way to compliment them. This is good practise even if you don't think this person is right for you. What goes around comes around! This is also a great building block for social skills improvement.5) Smart casual attire is always good for the first date. Girls - don't go over the top with jewellery. It looks crass and sometimes cheap! Subtlety is the name of the game here. Boys - don't swear or cuss. It only indicates ignorance and sometimes stupidity. It does not make you look tough. Your actions and the way you deal with life will show how tough you are quickly enough. Most people can find an adjective somewhere in their vocabulary to describe things. You'll find that you can too!6) Most girls like to be respected and despite their eye lashes fluttering away in some scenarios,ghd, they are generally quite bright and one step ahead of you. The more you treat them like your equal in conversation, the more quickly you will identify a good match for you or not.7) Most boys like to have interest shown in their achievements or interests. In fact, you could just focus on this for the whole date and be safe if you wanted to.8) Eat like a human being - don't quaff down the food like it's your last meal. Don锟? fill up. This will ensure that you can feel good about doing something after you've dined i.e. dancing, a walk evn consider about going to a differnt venue for coffee, dessert, dancing or a drink perhaps. Mixing you're venues often displays varying behaviour. If your date begins to swing from a chandelier after one drink you may want to consider the future carefully.9) Boys - if you enjoyed your date, say so at the end of the evening. Follow up with a thoughtful gift such as flowers to her place of work or her doorstep. It does NOT have to be expensive. The surprise is what counts here along with the fact that you have obviously thought about her since the date. Hand write the card and leave a phone number she can catch you on.10) Girls - try not to make yourself too available at the end of your first date. But make your feelings clear with an element of subtlety. Whatever you do not ask him if he will call again. Your mind set must be one of value and that if doesn't call then there will be another who will.One more thing - on your first few dates never and I mean never get in a discussion of old boy friends or girlfriends, ex wives or husbands,ghds, nor anything to do with these issues - Never! About the Author
Publisher & author: Roy Barker. Roy is the author of the popular ebook, Income from Photography - a downloadable ebook which guides the reader on how to start up and market a Profitable Photography business. It can be viewed at http://www.profitable-photography.com A Free eBook is also available which helps you decide on what type of photography you would enjoy most at http://www.photography-business.blogspot.com
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