Physics P2 Flashcards
Different types of reflection
Specular (smooth surface)and diffuse(rough surface)
What is rule for reflection
Angle of incidence is same as angle of reflection
Description of S-waves and P-waves
S-wave is transverse(secondary doesn’t go through liquid )
P-waves is longitudinal (Primary does go through liquid longitudinal like ripples in liquids) and is quicker than s-waves
What is the difference between a wave front diagram and a ray diagram
Wave front shows why the light refracts and changes direction by showing parts of the light slowing down
Ray diagram just shows the light reflecting and refracting
What is the symbol for concave and convex lenses in a ray diagram
Convex line with two arrows at the end pointing away
Concave line with two arrows at the end pointing in
What is the principle focus, focal length, lens axis in a concave and convex lens
Principle focus is where all the lines converge to in a convex lens and where the lines seem to come from in a concave lens
Focal length is the distance between the centre of the lens and the principle focus
Lens axis is the line going through the middle of the lens where if a light ray goes through it wont detract or change direction as the angle of incidence is 0
https://imgur.com/a/i1Yl9VB
What does diminished mean in terms of lenses
Means image has gotten smaller
Opposite of magnified
How do you draw a ray diagram
Draw a light ray from the top of image through the middle of the lens and axis
Draw another line from the top of the image parallel to the axis when it reaches the lens if convex it refracts towards the focal point if concave it follows the path of the focal point before the lens outward
The place the two lines meet is where the top of the real image is
If they don’t meet and are diverging then draw a dotted line going back and where the dotted lines meet is the top of the virtual image(where the image seems like it is coming from)
https://imgur.com/a/SjhOWDA
Example of Non contact force
Magnetic force, electrostatic force, gravity
Limit of proportionality
extension stops being proportional to force because it is inelastically deforming
Units for density of liquid
kg/m^3
What causes upthrust
When object is submerged in fluid a there is a force on it from every direction ,pressure increases with depth so force on bottom of the object is greater than force on top of an object that is submerged. The resultant force of this is upthrust
What is upthrust equal to
Upthrust is equal to the weight of the fluid that’s been displaced
Why will an object float or sink
If weight of object is more than upthrust it will sink, so if the weight of the object is more than the weight of the water displaced it will sink, so if density of object is more than density of water it will sink
Why is there less air pressure higher you go
Less air particles above so less of their weight decreasing pressure
And air gets less dense higher you go up because of gravity. Density decreasing means less particles to collide and cause pressure