To all the things that we do not perceive but are there for us to see are call Environmental Stimulus and we call Attended Stimulus to those things in our environment that catch our attention, the things to which we pay attention. One’s a perception happens we recognize the object or situation another proses began to transform this information into action according to our knowledge. This one is always influence by our knowledge, colors and interest. This information brought to a situation can be something learned time ago or knowledge gained by events previews to the present event. In this subject there are some tools that help us perceive they are call fundamental quintiles. They work thru our knowledge and help us recognize position, mass, or displacement.
Example on a play perception of the audience is different than what goes on behind the séance. Behind the séance there are so many thinks going on that we are not aware of. On the other hand for someone when is on the audience and has work as on a play would have a different perception then everyone else, he might see the nerviest from the actors, or would see details that no one else can see. This is because our knowledge changes the perception of what we see or hear. In this example we see that the Environment stimulus is all thinks that we can potentially perceive like the trees or flowers. Aon the other hand the attended stimuli would be the bear.

The process is constantly repeated all the time, our body gas sensors that constantly received information of the environment. This information travels in waves. The motion of waves like any other element is bound by forces that can change both the magnitude and direction of a motion. Newton's Laws required waves to be generated by some energy. Without energy there is no motion and without motion there is no wave.

Let’s consider a pendulum. If we observe carefully, we get the same number of swings in a unit of time no matter how high the pendulum swings right up until it stops swinging altogether! Most things that oscillate have the following characteristic: Each thing has a natural frequency of oscillation. If we don’t aply any force to the pendulum the oscillation is stop the resistence. On the other hand frequency can be manipulated. When we have a constat frequenzy we call it simple harmonic motion Suppose. On this simple harmonic motion we decide to force an oscillator at making a constant frequency by not letting it stop. Simple harmonic motion Goes back and ford same distance, periodic, Smooth constant change, Graphic gives a sinusoid. This can only happen with a force constantly goes against resistance making the net force to be cero.

On the example of the pendulum we can clearly see Newton’s Laws: An object moves with a velocity that is constant in mag¬nitude and direction unless acted upon by a non-zero net force. The acceleration of an object is directly proportional to the net force acting on an object and is inversely proportional to the mass of the object.
Is important to know oscillations and waves matter because that’s the way that sound and light travels. As we understand the way they travel we can understand the way out body perceived them. We see that an oscillation graphiquily is represented by waves. A wave requires three things A disturbance: This is something that can get our atoms moving. In music, this is usually an oscillator knocking into air particles. A medium: In the case of sound the movements of objects create a disturbance on the air crating waves, air is the medium, A connection between parts of the medium that transfers energy from one part to the other: In gases just like air this energy (sound) get transform from potential energy to kinetic energy when one particle knocks into another air particle.

Now we can decrive that sound is the vibration of any substance. The substance can be air, water, wood, or any other material, and in fact the only place in which sound cannot travel is a vacuum. When these substances vibrate, or rapidly move back and forth, they produce sound. Light has very similar attributes as the sound. Light is a wave of oscillating electric and magnetic fields perpendicular to the direction it’s going. Light can travel fine through a vacuum, which can have fields in it, but there can’t be sound in a vacuum because there’s no stuff there to oscillate.
This information of waves can help us understand Intensity and Sound Level as we understand that physics of sound waves. When we have two speakers we have found that we have areas of light and dark regions that rep¬resent compressions and rarefactions. The dark regions (where we don’t hear the sund ) are the crests of the waves. The same concept is apply for the dopler effect. As an ambulance speeds towards you, sirens blazing, the sound you hear is rather high in pitch. This is because the sound waves in front of the vehicle are being squashed together by the moving ambulance. This causes more vibrations to reach your ear per second. As you know, more vibrations per second results in a higher pitched sound. When the ambulance passes you, the sound becomes lower in pitch. Behind the ambulance there are fewer vibrations per second, and a lower sound is heard. This change in pitch is known as the Doppler Effect.