1. Why we introduce the concepts of work and energy? F ma CWE theorem r r total = CWE theorem Conservation of energy (More universal) 2. About the systems that we discuss Ignore the size, internal structure, internal motion, deformations, and thermal effects

Wave motion is the most universal physical phenomenon, we discover the wave motion all around us. Mechanical waves—acoustic wave, water wave Electromagnetic waves—radio, light wave Matter waves—electron wave

Collisions: All around us (cars, buses) Grand astronomical scale (stars, galexies) Nuclear, atomic and molecular physics The impulse-momentum theorem relates the change in the momentum of a system to the total force on it and the time interval during which this total forces acts

1. Differential equation of a simple harmonicoscillation and its solution

All around us: wheels, skaters, ballet, gymnasts, helicopter, rotors, mobile engines, CD disks, … Atomic world: electrons— “spin”, “orbit”. Universe: planets spin and orbiting the sun, galaxies spin, …

I．Choose the Correct Answer 1. An object is moving in a circle at constant speed v. The magnitude of the rate of change of momentum of the object （ C ）

I. Choose the Correct Answer . real engine has an efficiency of33%. The engine has work output of2 4J4 per cycle.how much heat energy is extracted from the high-temperature reservoir per cycle? (D) (A)8J

The causes of acceleration of a system--The first law of motion states that zero total force exists when the system has a constant velocity; a nonzero total force on the system causes its acceleration

The gravitational force 2. Newtons law of universal gravitation

1. The position vector and displacement Let the plane of the two-dimensional motion be the x-y plane of a Cartesian coordinate system