Physics flashcards (MCAT)

nearsighted (myopic)

- can focus on nearby objects, but cannot clearly see objects far away - nearsighted eye has a focal length that is shorter than is should be, so the rays from a distant object form a sharp image in front of the retina

plane mirror

- flat mirror that produces an image behind its plane at a distance equal to the object distance in front of the plane

Tubes open at both ends

- its fundamental resonant wavelength is twice the length of the pipe - both ends have displacement antinodes (max. amplitude) with a node in the middle of the pipe - pipe is 1/2 wavelength - resonant wavelength is independent of the diameter of the pipe

What occurs when a light wave and sound wave pass from air to glass?

- light slows down; sound speeds up - light slows down because the index of refraction is greater for glass than air - sound speeds up because the speed of sound in solid is much greater than in air

If the second floor and top floor of a building are separated by a distance of 100 m, what is the difference between the air pressures of the 2 levels? (air density=1.2 kg/m3 and g=10 m/s2)

- pressure = density x g x height - (1.2)(10)(1000)= 1200 N/m2

the properties of sound waves allow them to propagate through:

- solids, liquids, and gases only - for sound waves to propagate, there must be a physical medium consisting of atoms that can interact with each other

power

- the rate at which work is done

buoyant force

- upward force exerted on an object immersed in a fluid

pressure

-force/area or (density)(g)(height)

An object weighs 31.6N. When submerged in water, its apparent weight is 19.8N. What is the specific gravity of the unknown sample?

31.6/(31.6-19.8) = 31.6/11.8 = 2.68

hydrostatic pressure

the pressure at the bottom of a tube of height h filled with liquid of density r is given by rgh due to the weight of the liquid

speed of a wave

v=fλ, where λ=wavelength

An object with 15 grams mass is immersed in benzene and suffers an apparent loss of mass of 5 grams. What is the approx. specific gravity of the object? (specific gravity of benzene=0.7)

There was 5 g. of liquid displaced, thus the ratio is 15/5=3. The specific gravity of the object is 3 times the specific gravity of benzene (3x0.7=2.10) so the answer is 2.1

relation between distance, acceleration, and time

d = .5a x t^2

work

force x distance

total internal reflection

how light can be carried along a distance within a transparent material

In a nearsighted individual, the image of a distant object is focused:

in front of the retina, requiring diverging lens correction

Bernoulli's Equation

P + 1/2ρv^2 + ρgy = constant

power equations

P=IV P=I^2R P=V^2/R