Electromagnetic Waves 2
List the colors in order of highest frequency to lowest frequency.
VBGYOR
The influence that an object or charge has on other objects around it is called a __________.
Field
If a north pole and a north pole of two magnets are placed next to each other, will they attract or repel?
Repel! Like repels like.
This type of electromagnetic wave is used by firefighters and helicopter pilots to detect heat.
Infrared
These types of objects scatter light and make it appear blurry.
Translucent objects.
Unknown or mysterious
Electric fields always point from __________ to __________ charges.
Magnetic field lines always go from the _________ pole to the _________ pole.
North pole to the South pole
(think Santa Claus)
Visible Light
Name the three subtractive colors.
Cyan, magenta, and yellow.
These rays have the shortest wavelength and the highest frequency.
Gamma rays.
When rubbing a balloon on your head, the balloon takes on __________ charges and your hair takes on __________ charges.
What are the two kinds of magnets? Give an example of each.
Permanent: bar magnet
Induced: paperclip or iron nail
What makes up an electromagnetic wave?
Oscillating electric and magnetic waves that are perpendicular to each other.
These three colors of light combine to form white light.
Red, green, and blue (the additive colors)
What does the "100.3" stand for in the radio station FM 100.3?
The frequency of the electromagnetic waves in kHz.
Explain how bees use electric fields to collect pollen.
Pollen is generally negatively charged and bees are positively charged. When the bees come close, they detect the strength of the electric field around a certain flower. If other bees have been there recently, the strength of the field will be weaker.
Explain why a compass points north.
Molten iron in the earth's core creates an induced magnetic field. The metal in the compass aligns itself with the magnetic field lines surrounding the earth.
Name the 7 types of electromagnetic waves in order from longest to shortest wavelength.
Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
If an object appears cyan, which wavelengths is it absorbing?
Red! The object is reflecting blue and green light together, which looks cyan.
Explain how a microwave oven differs from a regular oven.
Regular ovens heat food from the outside in. Microwave ovens heat food simultaneously throughout by causing water molecules to rotate, thus creating friction.
What can cause a nail to become magnetic?
The movement of charges (electricity) creates a magnetic field.
Explain what causes a substance to be magnetic.
If the atoms' electrons spin in the same direction, the object will be magnetic.
What are the 3 kinds of UV light? Tell one fact about each.
UVA: Can be seen by the human eye.
UVB: partially blocked by the ozone layer and can cause sunburns.
UVC: blocked by ozone layer and can severely damage DNA. Used in hospital sterilization to prevent HAIs.
What happens to light when it enters our eyes?
The light is turned into electrical signals by three types of photoreceptors (red, green, and blue) on the back of our eyes (the retina).