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Speed and Velocity
Speed
- Speed is the rate of change in distance. In other words, it is how fast the distance change in 1 unit of time.
- In mathematics, displacement can be calculated from the following formula:
- Unit: ms^{-1}
- Type of quantity: Scalar quantity
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Acceleration
Acceleration
- Acceleration is the rate of velocity change.Acceleration is a vector quantity
- Formula:
- Unit: ms^{-2}
- Type of quantity: Vector quantity
- An object moves with a constant velocity if the magnitude and direction of the motion is always constant.
- An object experiences changes in velocity if
- the magnitude of velocity changes
- the direction of the motion changes.
- An object that experiences changes in velocity is said to have acceleration.
- An object traveling with a constant acceleration, a, if the velocity changes at a constant rate.
Equaitons for Uniform Acceleration
The above equation is for solving numerical problems involving uniform acceleration.
Summary of the Equation
Negative acceleration not necessary mean deceleration! Sometime, it mean the object moving in the opposite direction.
Distance
Distance is defined as the total path traveled by an object from one point to the other.
Displacement
Displacement is defined as the shortest distance between two point in a specific direction.
Speed
Speed is defined as the rate of change of distance.
Velocity
Velocity is defined as the rate of change of displacement.
Acceleration
Acceleration is defined as the rate of change of velocity.
Deceleration
Deceleration is the rate of decrease of velocity or how fast a velocity of a moving object decreases.
Introduction
- Kinematics is the research regarding the types of movement of an object without referring to the forces that cause the movement of the object.
- Movement along a straight line is called linear movement.
Distance and Displacement
Distance | Displacement | |
Definition | The distance traveled by an object is the total length that is traveled by that object. | Displacement of an object from a point of reference, O is the shortest distance of the object from point O in a specific direction. |
SI unit | meter (m) | meter (m) |
Quantity | Scalar | Vector |
Example 1 |
Distance Distance is a scalar quantity. Therefore we don’t need to tell the direction of point A and B from the reference point, O. |
Displacement
In the diagram above, the displacement of point B from the origin O is +100m, whereas the displacement of point A from the origin O is -100m. The + and – sign show the direction of the displacement. Displacement is a vector quantity. Therefore we need to tell the direction of point A and B from O.
Example 2
Adli go to work by motorcycle everyday as shown in the diagram above. The distance traveled by an object is the total length that is traveled by that object. The distance that Adli travels from his house to the factory is 200m.
Displacement of an object from a point of reference, O is the shortest distance of the object from point O in a specific direction. The displacement of Adli from his house after arriving at the factory is 120m.
In learning physics we need to carry out investigations. we gather information through observations and taking measurements. We measure many types of physical quantities. A physical quantity is a physical characteristic that can be measured. The value of the measurement consists of a numerical magnitude and unit. All physical quantities can be classified inti two groups : base quantities and derived quantities. Base quantity are quantity that cannot be defined interms of other base quantities. There are five base quantities : length, mass, time, current and temperature. Table 1.1 below shows the five base quantities and their respective SI units.
Base Quantity | Quantity symbol | SI unit | Symbol |
length | l | metre | m |
Mass | m | kilogram | kg |
Electric current | I | ampere | A |
Temperature | T | kelvin | K |
Time | t | second | s |
A derived quantity is one which obtained by combining base quantities by multiplication, division or both these operations.
Prefixes
We use prefixes to simplify the expression of very big or very small numerical values of pysical quantities. Prefixes are usually used to express some physical quantities that are either very big or very small.
Prefixes | Symbol | Value |
nano | n | 10^{-9} |
micro | µ | 10^{-6} |
milli | m | 10^{-3} |
centi | c | 10^{-2} |
deci | d | 10^{-1} |
kilo | k | 10^{3} |
mega | M | 10^{6} |
giga | G | 10^{9} |
Understanding physics
In physics, we study natural phenomena and the properties of matter.
The aim of physics is to explain the fundamental nature of the universe by using the concept of physics.
Physics involves the conduct of studies and experiments to find answers to the question ‘Why?’and ‘How?’ in relation to the mysteries of the universe.
The majority of natural phenomena can be explained using the principles of physics, for example;
i) Shadows are formed because light travel in straight line.
ii) Black objects are black because almost all the light that falls on them is absorbed.
Fields of study in physics:
Slide Show about Pascal Principle
Apa itu Fizik??
Fizik adalah salah satu daripada bidang akademik yang tertua, mungkin yang tertua menerusi kemasukannya di dalam bidang astronomi.
Fizik mengkaji tabiat dan interaksi antara jisim dan sinaran. Hukum fizik diluahkan sebagai persamaan matematik. Hukum ini mewakili usaha untuk mewujudkan kaitan antara data ujikaji berbeza. Kaedah saintifik pula mewakili usaha untuk menjelaskan hukum diperolehi dari ujikaji. Terdapat fahaman yang salah bahawa hukum fizik hanyalah teori mudah yang kita pasti.
inilah ajaibnya FIZIK..SAKSIKAN!!!