Read More
Date: 29-12-2016
1653
Date: 15-12-2016
1912
Date: 28-12-2016
1860
|
Instantaneous Velocity and Speed
When you drive to Chicago with an average velocity of 50 mph you probably don't drive at this velocity the whole way. Sometimes you might pass a truck and drive at 70 mph and when you get stuck in the traffic jams you might only drive at 20 mph. Now when the police use their radar gun and clock you at 70 mph, you might legitimately protest to the officer that your average velocity for the whole trip was only 50 mph and therefore you don't deserve a speeding ticket. However, as we all know police officers don't care about average velocity or average speed. They only care about your speed at the instant that you pass them. Thus let's introduce the concept of instantaneous velocity and instantaneous speed. What is an instant ? It is nothing more than an extremely short time interval. The way to describe this mathematically is to say that an instant is when the time interval Δt approaches zero, or the limit of Δt as Δt → 0 (approaches zero). We denote such a tiny time interval as dt instead of Δt. The corresponding distance that we travel over that tiny time interval will also be tiny and we denote that as dx instead of Δx. Thus instantaneous velocity or just velocity is defined as:
(1.1)
Now such a fraction of one tiny dx divided by a tiny dt has a special name. It is called the derivative of x with respect to t. The instantaneous speed or just speed is defined as simply the magnitude of the instantaneous veloctiy or magnitude of velocity.
|
|
اكتشاف تأثير صحي مزدوج لتلوث الهواء على البالغين في منتصف العمر
|
|
|
|
|
زهور برية شائعة لتر ميم الأعصاب التالفة
|
|
|
|
جمعيّة العميد وقسم الشؤون الفكريّة تدعوان الباحثين للمشاركة في الملتقى العلمي الوطني الأوّل
|
|
الأمين العام المساعد لجامعة الدول العربية السابق: جناح جمعية العميد في معرض تونس ثمين بإصداراته
|
|
المجمع العلمي يستأنف فعاليات محفل منابر النور في واسط
|
|
برعاية العتبة العباسيّة المقدّسة فرقة العبّاس (عليه السلام) تُقيم معرضًا يوثّق انتصاراتها في قرية البشير بمحافظة كركوك
|