
What is the difference between Scalar and Vector?
A scalar is a physical quantity that has magnitude but no direction. A vector, on the other hand, is a physical quantity that has both magnitude and direction. Operations of vectors satisfy the parallelogram rule or the triangle rule.

Point Mass and System of Particles
The range of the mass point model: 1. the size and shape of object can be ignored. 2. translating object or its all points has a same motion 3. rotation can be ignored.

What is the Time and how it is measured？
Periodic natural phenomena are used to define time. The rotation of the earth, the single pendulum, the spring oscillator and the resonance rate of atoms can all be used to define time.

Motion, Reference Frame, Coordinate System and Position
To determine whether an object is moving, you must first choose a frame of reference. A coordinate system is established in the reference system to accurately describe the motion of an object.

What is the difference between Distance and Displacement
Displacement is a fundamental concept in classical physics that describes the change in position of an object. Distance is the total length of the path an object travels between its starting and ending points.

Difference between Average Velocity & Average Speed
Velocity is the quantity that describes how fast or slow an object is moving. Average velocity: displacement/time interval. Average velocity: distance/time interval.

Difference between Instantaneous Speed & Instantaneous Velocity?
When the time interval is small, the difference between the average velocity and the instantaneous velocity is small. The instantaneous speed is equal to the magnitude of the instantaneous velocity.

Average acceleration & Instantaneous Acceleration
Acceleration describes how fast an object changes its velocity. If the velocity and acceleration are in the same direction, the object accelerates. In the opposite direction, the object decelerates. Perpendicular, the object's velocity is constant in magnitude and changes in direction.

Graphs of Uniform Rectilinear Motion and Time
We explored displacementtime graphs, velocitytime graphs, and accelerationtime graphs. We also investigated the meaning of the curve slope and the area enclosed by the curve and the coordinate axes.