Tiêu đề Chapter - 1 Motion.pdf ✅

ChemContent ● The distance travelled by an object in motion can never be zero or negative. ● The displacement of an object can be positive, zero or negative. Never can the distance travelled be less than the displacement. ● Both distance and displacement have the same units. Magnitude ● Magnitude is the size or extent of a physical quantity. In physics, we have scalar and vector quantities. ● Scalar quantities are only expressed as magnitude. E.g.: time, distance, mass, temperature, area, volume ● Vector quantities are expressed in magnitude as well as the direction of the object. E.g: Velocity, displacement, weight, momentum, force, acceleration, etc. Time and speed Time is the duration of an event that is expressed in seconds. Most physical phenomena occur with respect to time. It is a scalar quantity. Speed is the rate of change of distance. If a body covers a certain distance in a certain amount of time, its speed is given by Speed = Distance Time Uniform and Non-uniform Motion ● An object is said to be in uniform motion if it travels equal distances in equal intervals of time, howsoever small the intervals may be. ● An object is said to have non-uniform motion if it travels unequal distances in equal intervals of time. Uniform Motion: Definition: This type of motion is defined as the motion of an object in which the object travels in a straight line and its velocity remains constant along that line as it covers equal distances in equal intervals of time, irrespective of the duration of the time.