Physics's unit 3 Quiz

What is Coulomb's Law? What 2 physical things that can be changed in Coulomb's Law?

A mathematical definition for force due to electric charge. The amount of charge and distance between two charges.

What is wave interference? Give examples of both constructive and destructive interference.

A phenomenon that occurs when two waves meet while traveling along the same medium. The interference of waves causes the medium to take on a shape that results from the net effect of the two individual waves upon the particles of the medium. Wave interference can be constructive or destructive in nature. Constructive interference is 50 different people all singing the same note. Deconstructive interference is 50 different people all singing 50 different songs.

What is electric polarization (polarization of charge) for an object?

An object builds up a slight positive charge on one side and a slight negative charge on the other side (slight charge differentiation)

How does thin film interference occur? Give an example on thin film interference.

Constructive and destructive interference of light waves is also the reason why thin films, such as soap bubbles, show colorful patterns. This is known as thin-film interference, because it is the interference of light waves reflecting off the top surface of a film with the waves reflecting from the bottom surface. To obtain a nice colored pattern, the thickness of the film has to be on the order of the wavelength of light. The bright colors seen in an oil slick floating on water or in a sunlit soap bubble are caused by interference. The brightest colors are those that interfere constructively.

Describe how the TENS unit works?

Delivers small electrical impulses through electrodes that have adhesive pads that attaches them to one's skin. These electric impulses flood the nervous system, reducing the ability to transmit pain signals to the spinal cord and brain. Runs a electrical current through the body by a quad pole 2(+) and 2(-) run current through muscle making it contract and when the current is released it makes the muscle relax. It runs current through the nervous system and block the signal running along the nervous system( pain blocker).

Why would clothes appear a different color under fluorescent lights than in sun light?

Natural sunlight has all the spectrum of light, but florescent lights tend to miss some of the colors/shades, therefore clothes can only reflect the colors they can receive.

When sliding down a plastic playground slide you often hear a 'cracking' sound? What causes this?

The cracking sound is caused from friction between you and the slide. You are positively charged and the slide is negatively charged, as the electrons come back to you, the air molecules wiggle.

Why does light bend as it passes from air into water, plastic, glass, diamond, etc?

The different mediums refract differently, because one of the mediums causes the speed of light, the velocity and wavelengths to slow down, it change speed it changes direction.

How would you build an electromagnet?

To build an electromagnet you run an electric charge through a piece of conductive wire.

Describe what happens physically to produce a Doppler Effect? What is an example of the Doppler Effect used in everyday life?

To physically produce a Doppler effect a wave source or receiver is in motion, the wavelength and frequency lengthens and shortens. when frequency is shorter , wavelength is longer. Mosquito pitch in sound will change as it moves away from you or towards you.

What is the difference between transparent and opaque? Give an example of something which is transparent to visible light but opaque to some other form of light. Give an example of something which is opaque to visible light but transparent to some other form of light.

Transparent objects allow light to pass through them , whereas opaque ones allow no light to pass through. Clouds are opaque to visible light but transparent to other forms of light such as UV (sunburn on a cloudy day).

What is the critical angle and how is total internal reflection related to it? Give an example of total internal reflection.

When light is trying to move from a high to a low density material, the light bends toward the surface. The critical angle is the first angle at which total internal reflection occurs(no light can escape). All of the angles between the critical angle and the surface have total internal reflection. Swimming under the water, at a certain angle, you look up and you can see the bottom of the pool because of one internal reflection.

How do you strengthen or weaken a magnet?

You strengthen a magnet by lining up the domains. You weaken a magnet by moving the domains further away.

What is diffraction? Give an example how diffraction is observed in everyday life.

the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture Ocean waves bending around a humans legs who is standing in the water.