Physics

Discovering Physics

• Study of properties behavior & interaction between matter and energy.
• From the Greek word ‘physike’ meaning ‘nature’
• Study of natural phenomena
• Investigates and formulates the fundamental laws of nature

History/Development of Physics(first named as__ then became __ e.g.)

1.natural philosophy

*pre-socratic philosophers like Thales refused supernatural reasons. They proposed ideas verified by reason and observation and many of their hypotheses proved successful in experiment.

2.natural science

*  Quantitative descriptions became popular among physicists and astronomers

*experimental physics had its debut

3.classical physics

*laws of physics;thermodynamics;chemistry;electromagnetics

4.modern physics

*quantum physics; examples are x-rays, nuclear physics, radioactivity,  atomic physics, and theory of relativity

*Einstein the founder/creator/whatever synonym, of modern physics 

Historic People

-Isaac  Newton (discovery of gravity;laws of physics)

-Albert Einstein (modern physics)

-Johannes Kepler (laws of physics)

-Galileo Galilei (laws of physics)

Chapter2 Motion 

• change in position of an object with respect to time.

 Newton's laws of motion

1. first law(Galileo's law of inertia): the velocity of a body remains constant unless the body is acted upon by an external force.
2. second law: the acceleration(a) of a body is parallel and directly proportional to the net force(F) and inversely proportional to the mass (m) i.e. F=ma
3. third law: the mutual forces of action and reaction between 2 bodies are equal, opposite, and collinear

examples:

first law- A ball doesn't move unless kicked.

second law- Mike's car, which weighs 1,000 kg, is out of gas. Mike is trying to push the car to a gas station, and he makes the car go 0.05 m/s/s. Using Newton's Second Law, you can compute how much force Mike is applying to the car. 

F=1000x0.05

F=50newtons

3rd law- The rocket's action is to push down on the ground with the force of its powerful engines, and the reaction is that the ground pushes the rocket upwards with an equal force.

Free Fall Motion

                -motion under the influence of gravity only

                -air resistance is neglected and acceleration is constant

Case 1: Objects dropped

Case 2: Objects thrown downward

Case 3: Objects thrown upward

Types of motion

• Simple harmonic motion – (e.g. pendulum).
• Linear motion – motion which follows a straight linear path, and whose displacement is exactly the same as its trajectory.
• Reciprocating (i.e. vibration)
• Brownian Motion (i.e. the random movement of particles)
• Circular motion (e.g. the orbits of planets)
• Rotary motion – a motion about a fixed point ex. the wheel of a bicycle
• Curvilinear Motion – It is defined as the motion along a curved path that may be planar or in three dimensions.
• Rotational Motion - ( e . g .[ferris wheel]

this is just nothing, I just want to share the reviewer my classmate made, thanks to her, we just have to study :D this blog became so random (lmao)