MCAT Physics 2014 Flashcards
Which waves consist of both longitudinal and transverse waves?
water waves;
earthquake waves
T/F:
Longitudinal waves can’t be polarized.
tru
There are traveling waves, and there are also _____ waves.
standing
What is a standing wave?
wave that is trapped in a cavity
What is the main difference between standing waves and traveling waves?
(hint: frequencies)
Standing waves have only certain allowed frequencies
What is a fundamental?
(waves)
The lowest possible frequency for a given standing wave.
The 2nd lowest frequency achievable by a given standing wave is called:
second harmonic
If the spring constant for a given spring is K, then what is the frequency of that spring’s oscillation?
T/F:
The speed of a wave is determined by its frequency.
fals
When a wave passes from one medium into another, its _____ changes, but its _______ does not.
speed;
frequency
What determines the velocity of a wave traveling thru a given medium?
- The type of wave
- the characteristics of the medium
The MCAT may refer to Potential Energy as ____ energy.
mechanical
An oscillating electrict charge generates a/n ______.
electromagnetic wave.
Describe the wave-particle duality.
EM radiation travels liek a wave, but interacts with matter like a particle.
The ratio of the speed of light in a vacuum, to the speed of light in a given medium, is called:
Index of refraction
What is the Index of Refraction?
The ratio of the speed of light in a vacuum, to the speed of light in a given medium, is called:
The higher an object’s Index of Refraction, the [faster / slower] light travels thru that object:
slower
A ray of light travels from one medium into another. The light bends (refracts) when it enters the 2nd medium.
If the 2nd medium has a higher index of refraction than the incident (first) medium, then the ray will bend [away from / towards] the normal.
towards
A ray of light travels from one medium into another. The light bends (refracts) when it enters the 2nd medium.
If the 2nd medium has a [higher / lower] index of refraction than the incident (first) medium, then the ray will bend away from the normal.
lower
What is Snell’s Law?
n1 * sin θ1 = n2 * sinθ2
How do you figure out the critical angle for total internal reflection?
sinθcrit =
(n of the medium beyond the boundary / n of the medium through which “incident” ray is traveling)
When light passes from one medium into another, there can be a critical angle for total internal reflection ONLY if:
if the n (index of refraction) of the original medium through which the “incident” ray travels, is GREATER than the n of the other medium beyond the boundary.
When white light is split into its monochromatic individual colors, _____ light bends the least, while ______ light bends the most.
RED the least;
VIOLET the most
When talking about lenses and mirrors, what does f stand for?
focal length
In optics, what is focal length?
distance, from mirror/lens, to focal point
[concave / convex] mirrors have an imaginary focal point
conVEX
What is a real image?
An image is real if light rays focus at the position of the image.
What is a virtual image, as opposed to a real image?
an image is virtual if light rays don’t focus at the apparent location of the image
Based on the Mirror Equation (oif) , how do we know that an image is real or virtual?
A positive value for i → image is in front of mirror and is real
A negative value for i → image is behind mirror and is virtual
In optics, What does it mean if i is positive?
image is real
T/F:
Virtual images can sometimes be upright
fals (technically)
Virtual images are ALWAYS upright.
In optics, _____ images are inverted.
real
In optics, _____ images are upright.
virtual
T/F:
In optics, if i is postive, then m is negative.
tru
And if i is negative, then m is positive.
For mirrors, f is positive if:
the mirror is concave.
In optics, f is negative for mirrors when:
the mirror is conVEX.
T/F:
Real images are always inverted.
tru
Lenses that are thicker in the middle are called _____ lenses.
converging
When switching between mirrors and lenses, which value(s) switch from positive to negative? (o, i, f)
f
f is positive for a _____ lens.
convex / converging
A convex lens is the same thing as a _____ lens.
converging
For lenses, ______ images are formed on the same side of the lens as the object
virtual
What is the relationship between a lens’s f (focal length) and its power.
the shorter the focal length (f), the greater the power
What is a diopter?
a unit that measures lens power in 1/meter, or meter-1
What is the image-drawing method for a converging/convex lens?
see p. 231, MCAT PHYSICS
What is the image-drawing method for a diverging/concave lens?
p. 231 of MCAT Physics
- What is the image tracing method for a concave mirror?
- For a convex mirror?
see p 235 of MCAT Physics
Two identical electronic devices are connected to the same electrical circuit, in parallel to each other.
Compared to the voltage generated by a single device, the total voltage supplied by the 2 parallel devices will be:
the same.
Two identical electronic devices are connected to the same electrical circuit, in series to each other.
Compared to the voltage generated by a single device, the total **voltage **supplied by the 2 devices will be:
the sum of the two individual voltages. So add the two individual voltages together.
T/F:
*Identical *voltage sources, connected in parallel, produce the same output (total) **voltage **as a single source.
tru
T/F:
*Identical *voltage sources, connected in series, produce the same output (total) **voltage **as a single source.
fals
State Pascal’s Law
if you apply pressure on a liquid, the pressure is transmitted equally to all parts of the liquid.
Give the formula for Pascal’s Law
If given a point that is deep inside a body of water, how do we calculate the pressure of water exerted on that given point?
guage Pressure = ρ*g*h
ρ → density of water/fluid
g → acceleration from gravity
h → how deep, under water,
State Archimedes’ Principle
buoyant force on an object =
weight of the fluid that is **displaced **by the object.
Give the eqn for Archimedes’ Principle:
**FB **= weightdisplaced =
(massdisplaced)*(g) = (ρfluid)*(Vsubmerged)*(g)
Give the eqns for finding Buoyant Force on an object.
**FB **on object =
weightdisplaced fluid = (massdisplaced fluid)*(g) = (ρfluid)*(Vsubmerged)*(g)
If the object is COMPLETELY submersed:
FB = [(massobject)*(g)] * (ρfluid) ÷ (ρobject)
FB = (weightobject) * (ρfluid) ÷ (ρobject)
When talking about Floating objects, what is the important ratio to remember?
Volumedisplaced ÷ Total Volume of Object
=
Densityobject ÷ Densityfluid
