Physics Notes PDF

STATICSCH5 STATICS| branch of mechanics that deals with the study of bodies at rest under a number of forces. ‫االتزان‬ Equilibrium | ‫الشرط الذهبي هو ان في النهاية المؤثرات تساوي صفر‬ if it is at rest or moving with uniform velocity. linear and angular acceleration of a body is zero, Static equ...

STATICSCH5 STATICS| branch of mechanics that deals with the study of bodies at rest under a number of forces. ‫االتزان‬ Equilibrium | ‫الشرط الذهبي هو ان في النهاية المؤثرات تساوي صفر‬ if it is at rest or moving with uniform velocity. linear and angular acceleration of a body is zero, Static equilibrium| Dynamic equilibrium| when a body is in a state of uniform motion and the resultant of all forces acting upon it is zero ex : Jump by using a parachute. If the combined effect of all the forces acting on a body is zero ex : All stationary bodies Conditions of equilibrium | all the forces acting on the body are equal to zero. States of equilibrium | the vector sum of all the torques acting on it is zero. Reason of stability ‫اذا رفعنا الكتاب راح يرتفع‬ ‫مركز الثقل و خط تاثير الوزن‬ Stable equilibrium ‫يمر في قاعدة الكتاب وراح‬ the center of gravity of a body lies below the point of suspension Unstable equilibrium When the center of gravity of a body lies above the point of suspension Neutral equilibrium the center of gravity of a body lies at the point of suspension “FRS” ‫يسبب عزم دواران بسبب‬ ‫وزن الكتاب و راح يرجع‬ ‫الكتاب الى موضعه االصلي‬ Reason of in stability ‫اتزان القلم هو‬ ‫سبب عدم‬ ‫الى اهتزاز راح‬ ‫اذا تعرض‬ ‫زكز الثقل و خط‬ ‫يتخفض م‬ ‫القلم و بيكون‬ ‫تاثير وزن‬ ‫خارج القاعدة‬ neutral Reason of ‫الفكرة‬ ‫ان الكرة‬ ‫راح يكون‬ ‫مر‬ ‫كز‬ ‫ا‬ ‫لث‬ ‫قل‬ ‫في نفس‬ ‫المكان‬ ‫(ال‬ ‫ي‬ ‫تم‬ ‫رف‬ ‫عه وال يتم‬ )‫خفضه‬ ‫ف اذا مش‬ ‫ينا الكورة‬ ‫النق‬ ‫طة‬ ‫ر‬ ‫اح‬ ‫تكون في‬ ‫نفس‬ ‫م‬ ‫كان‬ ‫ها‬ ‫ما تتغير‬ WORK OF SECTION 2 2024102322 STATICSCH5 TORQUE| The tendency of a force to produce rotation in a body about an axis is called torque or momentum of force. ‫عزم الدوران‬ ‫طول الذراع‬ Torque = (force ) ( moment arm) ‫القوة المؤثرة‬ Center of gravity | The center of gravity of a body is a point where the total weight of the body is concentrated. It is not necessary that the center of gravity should be within the body Center of gravity of different objects | Rectangle The center of gravity of a rectangular is at the point of intersection of its diagonals. Circle Center of gravity of a circle is at its center Square Center of gravity of square is at the point of intersection of its diagonals. “FRS” Regular bar The center of gravity of a regular bar is at its geometrical center. Triangle The center of gravity of a triangle is at the point of intersection of its medians Cylinder The center of gravity of a cylinder is at the axis of cylinder. WORK OF SECTION 2 2024102322 WORK POWER AND ENERGYCH6 WORK| )‫ازاحة‬-٢( )‫قوة‬-١( ‫يعني عشان نقول انه شغل الزم يكون فيه‬ When a force is applied to a certain object and displaces it through a certain distance, the work is said to be done. W= F ⋅ d. S.I. unit is Nm or Joule. W = F d cos θ ‫نفس الفكرة بس بيكون بوجود زاوية‬ W ‫الشغل‬ F ‫القوة‬ d ‫االزاحة‬ cos θ ‫الزاوية المعطا‬ Work is the maximum When F and d are parallel to each other work is zero F d x1 (cos 0° = 1) ‫يعني اذا واحد يساوي الصفر بيكون الشغل صفر‬ Force (F) is zero. Displacement ( d )is zero. Angle (θ) is 90° i.e. cos 90° = 0 work is negative The work done by F is –ve when F and d are oppositely directed F d (-1) (cos 180° = -1) POWER| work of 1 J is don in 1s the power is 1 watt horse power hp 1hp=746w “FRS” WORK OF SECTION 2 2024102322 WORK POWER AND ENERGYCH6 ENERGY| The ability of a body to do work is called Energy. It is a scalar quantity Its SI unit is Joule. basic kinds of energy| Kinetic Energy Potential Energy Kinetic Energy The energy that objects possess due to their motion KE m v Potential Energy ‫الطاقة‬ ‫الحركية‬ ‫الكتلة‬ ‫السرعة‬ The energy stored in a body, which is ready to be used EX; Elastic Potential energy Chemical Potential energy. Gravitational potential energy. ‫مهم مهم جدا‬ “FRS” WORK OF SECTION 2 2024102322