REVIEW
Let’s begin with some review What are two types of mirrors we talked about? What property of light allows shadows to form? Where does an incident ray of light come from? In a ray diagram, what is a normal? Why can’t we see things around corners?
More Review What is the difference between a Penumbra and Umbra? What is it called when an electromagnetic wave bends because it travelled from one medium into another? Why would you want your satellite dish (for watching TV) to be concave in shape, and not convex?
Physical Science: Optics Mirrors, Mirrors, Mirrors
Concave mirrors Concave mirrors are good for collecting light rays into a single point Light rays will converge to a single point Called the focal point
Concave mirrors Images produced by concave mirrors appear differently: 1. If the object is far away, then the image is small and inverted 2. If the object is between the focal point and the mirror, then the image is larger than the original object, and is upright
Diagrams to show how images will be produced
Convex mirrors Convex mirrors are good for reflecting light so they spread far apart. This allows us to see a wider area than normal Light rays reflect and spread apart. This is described as diverging
Convex mirrors Images produced by convex mirrors have 2 characteristics: 1. Objects appear smaller than they are 2. A wider view can be seen with a convex mirror compared to a plane mirror of same size Draw diagram
YOUR TEST WILL BE A WEEK AND A HALF FROM NOW ON JANUARY 28TH, DAY 4 THIS THURSDAY, JANUARY 22ND, WE WILL HAVE A REVIEW SESSION WRITE DOWN QUESTIONS, BRING THEM TO CLASS. AND ASK THEM!
Physical Science: Optics Concave and convex lenses
Concave lenses Concave lenses are thinner in the middle than at the edges Light is refracted and diverge apart Images formed by concave lenses are always smaller and upright
Concave lenses
Convex lenses Convex lenses are thicker in the middle than on the edges Parallel light rays refracts and converges to a focal point
Physical Science: Optics Outcome C3 – Comparing visible light to other types of electromagnetic radiation
Review: Electromagnetic radiation Electromagnetic radiation is the transmission (movement) of energy in the form of waves. These waves range from long radio waves to very short gamma rays The electromagnetic spectrum is the range of energies that include long radio waves, microwaves, infrared waves, visible light waves, ultraviolet waves, X-rays and gamma rays.
Electromagnetic spectrum
TURN TO YOUR PARTNER (TTYP) Question: Using the figure provided to you, answer: Wavelengths longer than visible light include????? 30 SECONDS TO THINK OF AN ANSWER WITH YOUR PARTNER TIME IS UP 15 SECONDS LEFT Wavelengths shorter than visible light include????? 30 SECONDS TO THINK OF AN ANSWER WITH YOUR PARTNER TIME IS UP 15 SECONDS LEFT
Electromagnetic radiation – WHAT IS IT EVEN GOOD FOR?! Other types of electromagnetic radiation include: Radio waves microwaves
So what does this all mean? Long Radio waves - Useful for communication Microwaves – heats up our food X-rays – The energy can travel through our skin, but is blocked by our bones
Electromagnetic radiation – WHAT IS IT EVEN GOOD FOR?! Other types of electromagnetic radiation include: Infrared Ultraviolet
Electromagnetic radiation – WHAT IS IT EVEN GOOD FOR?! Other types of electromagnetic radiation include: X-rays gamma rays
Electromagnetic radiation How are these different? TURN TO YOUR PARTNER AND ANSWER: What 3 differences do specific electromagnetic radiation have from one another… For example: Contrast UV rays to Radiowaves ONE MINUTE TO THINK OF AN ANSWER WITH YOUR PARTNER TIME IS UP 30 SECONDS LEFT