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Rotation of a Rigid object about a fixed axis

الكلية كلية التربية للعلوم الصرفة     القسم قسم الفيزياء     المرحلة 1
أستاذ المادة فؤاد عطية مجيد       29/05/2018 09:22:55
Collision / Impulse
When two objects collide, the force they exert on each other usually act only for a short time. Such forces are called impulsive forces during the collision the impulsive force produce a large change in the motion of the object while any other forces present produce only small changes usually neglected. During a time interval dt, the momentum change by:
dp ?=F ?dt
Integrating over the time of collision
p ?_f-p ?_i=?_(p_i)^(p_f)??dp ? ?=?_(t_i)^(t_f)?F ? dt
J ?=?_(t_i)^(t_f)?F ? dt [impulse]
?p ?=p ?_f-p ?_i=J ???p ?=J ?=F ??t
7.5 Collisions
We want to study the collision of objects how they move (velocities) after collision. In special cases momentum conservation is sufficient. In general it is not enough. Can categorize collisions in terms of two types:
Elastic Collision
Interaction forces are conservative
Total kinetic energy is the same before and after collision
Momentum is conserved K_i=K_f, p ?_i=p ?_f
Inelastic collision
Inelastic Collision
Collision in which KE is not conserved are called inelastic collision. Some the energy is absorbed and converted to other forms. If the amount of KE absorbed is a maximum that is allowed by a momentum conservation, the collision said to be perfectly inelastic. In practice almost all collisions are inelastic to some degree.
Sticking collision- one dimension
Two particles masses m_1 and m_2 move with velocities v_1i and v_2i along a straight line. They collide stick, moving as a unit with velocity v_f after the collision.
Total momentum is conserved
p ?_i=p ?_f
m_1 v ?_1i+m_2 v ?_2i=(m_1+m_2)v ?_f
v ?_f=(m_1 v ?_1i+m_2 v ?_2i)/(m_1+m_2 )
Sticking collision- two dimension
Linear momentum conserved
Two equations, one for each component
tan?=(m_2 v_2)/(m_1 v_1 )
v=m_2/(m_1+m_2 ) v_2/sin?
Elastic Collision
Total energy is conserved


المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .