BP/Kaplan/AAMC Physics

Question 1

A higher Reynolds number makes a fluid more likely to be

Answer 1

A higher Reynolds number makes a fluid more likely to be turbulent.

Question 2

Increasing temperature decreases …

Answer 2

Increasing temperature decreases viscosity.

Question 3

The Venturi effect says that when a tube narrows, the velocity …

Answer 3

increases and the pressure decreases. Thus, the narrow end of the tube has the lowest pressure and the larger end has the highest pressure.

Question 4

The Reynolds number (which indicates the likelihood of turbulence) is directly related to …
Increasing the viscosity would therefore result in …

Answer 4

The Reynolds number (which indicates the likelihood of turbulence) is directly related to the velocity and density of the fluid and inversely related to its viscosity. Increasing the viscosity would therefore result in a lower Reynolds number and thus a smaller likelihood of turbulence.

Question 5

density of water in g/cm^3

Answer 5

1, or 1000 kg/m^3

Question 6

The law of conservation of energy states that

Answer 6

The law of conservation of energy states that energy is neither created nor destroyed, it only changes form. In other words, energy is only ever transferred. This example illustrates a transfer of energy from the bat to the ball, so it supports the law of conservation of energy.

Question 7

DO U NEED the angle of incline to find work? which angle do u need? does work depend on path or no?

Answer 7

. The angle of incline is not necessary to calculate work done. The angle of importance is the angle between the force and displacement. The amount of work done to change the elevation of the object is independent of path.

Question 8

For ramps, the ideal mechanical advantage can be calculated as follows:

Answer 8

For ramps, the ideal mechanical advantage can be calculated as follows: mechanical advantage = length of incline / height of incline. Intuitively we can picture that a ramp with a minimal angle of incline is going to have a very large length of incline to achieve a certain height of incline. The more we increase the angle of incline, the more we shorten the length of incline and decrease the overall mechanical advantage.

Question 9

Moving a heavier box would also increase the amount of …

Answer 9

work that needs to be done, as the total change in potential energy of the box is now greater, therefore the amount of work that needs to be done on it to move it above your head will be greater as well.

Question 10

work is…

Answer 10

Work can be a path dependent and a path independent variable. It depends on what type of force is being applied to do the work. Friction is a non-conservative force – work done against friction is path dependent. (google, prospectivedoc.com)

Question 11

how do things move in electric field lines

Answer 11

A negatively charged particle such as an electron will move in the direction opposite the direction of the electric field lines; recall that electric field lines point away from positive charges and toward negative charges, which is the opposite of the way a negatively charged particle would move in the presence of those charges.

Question 12

what does it mean if two pts are on the same equipot line?

Answer 12

The two points are located on the same equipotential line, meaning they are at regions of equal electric potential. Therefore, P2 – P1 must be equal to zero.

Question 13

the charge gained e PE, so what does this mean? what are the units of electric potential? how can we find e potential?

Answer 13

The charge gained electric potential energy, and thus must have moved from a region of low to high electric potential. The units of electric potential are volts, or joules of energy per coulomb of charge. We know that the charge gained 12 joules of energy. Therefore, to find the electric potential we can divide the electric potential energy by the number of coulombs of charge moved.

Question 14

The strength of a magnetic field generated by a moving charge is proportional to what? what does this mean in terms of speeds of particles

Answer 14

The strength of a magnetic field generated by a moving charge is proportional to the velocity and charge of that particle. A faster moving particle will generate a stronger magnetic field than a slower moving particle, given equal charge. Two particles of equal velocity will produce magnetic fields whose relative strength depends on their charge.

Question 15

what is the lorentz force and what can it also be called

Answer 15

The Lorentz force is the electric force plus the magnetic force experienced by a charged object – also known as the electromagnetic force.

Question 16

what cant magnetic fields act on

Answer 16

Magnetic fields cannot act on objects with a velocity vector that is parallel to the direction of magnetic field lines.

Question 17

When considering the right hand rule for determining the direction of a magnetic field created by a moving charge, a person’s thumb will point in the direction of …

Answer 17

positive charge movement. This is the same direction as current’s flow through circuitry.

Question 18

can a material with a large bulk modulus be compressed and what does this mean

Answer 18

A material with a large bulk modulus is not compressible, which means sound waves have an easier time traveling through the medium. a bulk modulus is the measure of a mediums resistance to compression

Question 19

doppler effect eqn- when is the velocity of the SOURCE negative or positive?

Answer 19

The velocity of the source (vs) is negative when the source is moving towards the observer and positive when the source is moving away from the observer. Since the police car is moving towards Susan, the police car’s velocity is negative.

Question 20

doppler effect eqn- when is the velocity of the OBSERVER negative or positive?

Answer 20

The velocity of the observer (vo) is positive when the observer is moving towards the source and negative when the observer is moving away from the source. Since Susan is driving away from the police, her velocity is negative.

Question 21

what units are to be used for doppler eqn

Answer 21

use hz when doing doppler

Question 22

what does the venturi effect state about liquid speeds and pressure exerted on surroudings

Answer 22

The Venturi effect states that when a fluid starts moving faster, it exerts LESS pressure on its surroundings.

Question 23

True or false: The gauge pressure of my tires at sea level was 50 psi. After driving up into the mountains, I would expect the gauge pressure to drop slightly.

Answer 23

False. Gauge pressure is given by the equation: PG = PT - Patm , where PT is the total pressure and Patm is the atmospheric pressure. Driving up into the mountains should cause the atmospheric pressure to drop, but we would expect the pressure inside the tire to stay the same. Because gauge pressure is the pressure inside the tires compared to outside, we should have a HIGHER gauge pressure than we had before.

Question 24

specific gravity

Answer 24

density of the liquid / density of water

Question 25

density of water (know all of these)

Answer 25

1000 kg/m3, 1 g/mL, 1 g/cm^3, 1kg/L

Question 26

concave meniscus

Answer 26

goes in. happens when adhesive >cohesive

Question 27

convex meniscus

Answer 27

rounds out. happens when adhesive<cohesive

Question 28

why is water more likely to form a convex meniscus

Answer 28

bc it has strong cohesive interactions

Question 29

what can apply a bouyant force

Answer 29

Any fluid can apply a buoyant force, including all gases and liquids.

Question 30

what type of harmonics can there be for closed tubes

Answer 30

For closed tubes, there can only be odd number harmonics.

Question 31

ultrasound and ultraviolet waves are, respectively

Answer 31

longitudinal, transverse

Question 32

does freq change when going btwn mediums

Answer 32

When light moves from a lower-index medium into a higher-index one, its velocity decreases and so wv must decrease too. freq doesnt change when going btwn mediums

Question 33

when can total internal reflection occur

Answer 33

Total internal reflection can only occur when attempting to transition the other way (from a high-index material into a low-index one).

Question 34

The magnetic field component of an electromagnetic wave is always:

Answer 34

Electromagnetic waves are composed of oscillating electrical and magnetic fields, oriented perpendicular to each other but both propagating in the same direction. The direction of propagation of an EM wave is perpendicular to both the electrical and magnetic field planes.

Question 35

what does the speed of an emag wave depend on

Answer 35

The speed of an electromagnetic wave does not depend on the intensity, color or polarization. it does depend on the medium

Question 36

sound waves are

Answer 36

longitudinal

Question 37

what kind of images will light rays hitting a plane mirror produce

Answer 37

Light rays hitting a plane mirror will produce virtual images as shown below.

Question 38

True or false: In a two lens system where the object has a height of 3 meters and the final image is upright and has height 2 meters, the magnification of every lens in the system multiplied together must equal 2/3.

Answer 38

This statement is true. Each lens in a two-lens system has a given magnification, which can be multiplied together to find the net magnification of the system. For the height of the final image of a system to be equal to 2/3 the height of the original object, all magnifications must multiply together to equal 2/3.

Question 39

True or false: In this ray diagram with a concave mirror, the location, size, and orientation of the image are correctly depicted.

Answer 39

This statement is false. The image for an object located outside a concave mirror’s center of curvature will produce a real, inverted image. The image shown in the question stem is incorrectly depicted as upright.True or false: In this ray diagram with a concave mirror, the location, size, and orientation of the image are correctly depicted.

Question 40

A two lens system is comprised of one lens with a magnification of -40, and a second lens with a magnification of ¼. An image created by this system will be how much bigger than its original object?

Answer 40

The net magnification of a two-lens system can be found by multiplying the magnification of each lens. The net magnification of this system is found by multiplying -40 and ¼, which equals -10.

Question 41

The conversion between focal length and diopters is:

Answer 41

The conversion between focal length and diopters is:

Diopters (1/m) = 1/Focal length (m)

Question 42

mirrors v lenses in terms of what they do

Answer 42

Mirrors fully reflect light, whereas lenses are primarily intended to refract light.

Question 43

A concave mirror has a focal length of 10 meters, and an object distance of 3 meters. Which terms accurately describe the image produced by this mirror?

Answer 43

Concave mirrors may produce real or virtual images. When a concave mirror reflects light from an object inside of its focal distance, the image is virtual, meaning that it appears to exist on the opposite side of the mirror where no rays of light are actually converging. Virtual images have a positive magnification, meaning that this image is upright.

Question 44

True or false: a real image is formed when reflected light converges toward a single point.

Answer 44

true

Question 45

what are mirrors defined by

Answer 45

Mirrors are defined by their ability to reflect light without refracting or absorbing it to any significant extent.

Question 46

plane mirrors only produce

Answer 46

virtual images

Question 47

power formula

Answer 47

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

Question 48

energy in terms of power

Answer 48

E= PT

Question 49

what is a real image?

Answer 49

real- describes an image on the same side of a lens or mirror as the refracted or reflected light that can be projected on a screen- in single mirror or single lens sytems, they are always inverted.

Question 50

what is a virtual image?

Answer 50

describes an image on the opposite side of a lens or mirror as the refracted or reflected light. in single mirror or single lens systems, they are always upright

Question 51

formula for resistance

Answer 51

R= densityL/A

Question 52

voltage drops of resistors in series and their resistances

Answer 52

Vs=V1+v2+vn
Rs=R1+R2+r3

Question 53

voltage drops of resistors in parallel and their resistances

Answer 53

Vp=V1=V2=V3
Rp=1/R1+1/R2+1/R3

Question 54

resistor

Answer 54

Resistor is defined as an electrical component which is used for controlling temperature and voltage

Question 55

capacitor

Answer 55

A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance

Question 56

A glass fiber carries a light digital signal long distances with a minimum loss of amplitude. What optical property of glass allows this phenomenon?

Answer 56

Light can be carried along a distance within a transparent material by means of total internal reflection

Question 57

can sound waves travel in a vacuum

Answer 57

no, they require a medium

Question 58

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

Answer 58

The buoyant force on the solid is the difference between its weight (31.6 N) and its apparent weight in water (19.8 N). This force equals the weight of the water displaced, which, in turn, equals the product of the volume of the solid and the density of water. The specific gravity of the solid, i.e., the ratio of its weight to the weight of an equal volume of water, is then: 31.6/(31.6 -19.8) = 2.68. The correct answer is B.

Question 59

what is a harmonic

Answer 59

a half wavelength

Question 60

how to find the harmonics for an open pipe

Answer 60

the number of nodes

Question 61

how to find the harmonics for an closed pipe

Answer 61

number of quarter wavelength

Question 62

formula of a harmonic

Answer 62

fn = n * f1

Question 63

what are pitches related to

Answer 63

frequency

Question 64

Diverging lenses always have negative ______ _______.

Answer 64

Diverging lenses always have negative focal lengths

Question 65

The Doppler effect allows the observer to distinguish between

Answer 65

The Doppler effect allows the observer to distinguish between a stationary and a moving object that reflects ultrasound waves

Question 66

Capacitance in series circuits

Answer 66

1/c= 1/c1+1/c2

Question 67

capacitance in parallel

Answer 67

c= c1+c2+c3

Question 68

For maximum torque, a force should be exerted at a _____ angle to the lever arm. For maximum work, a force should be exerted at a ______ angle to the desired displacement.

Answer 68

90 degree, 0 degree

Question 69

all mirrors or lenses w positive focal lengths represent

Answer 69

converging systems

Question 70

to find efficiency u use what

Answer 70

w/qh or (qh-qc)= 1- (qc/qh)

Question 71

the bicarb ion can act as an acid bc

Answer 71

it has an acidic proton

Question 72

converging mirrors are concave but converging lenses are

Answer 72

convex

Question 73

when is the angle of incident greater than or equal to the critical angle

Answer 73

at total internal reflection

Question 74

Light can be carried along a distance within a transparent material by means of

Answer 74

total internal reflection.

Question 75

what does electrical force depend on

Answer 75

Electrical force depends on the particle’s charge and the strength of the electric field experienced by the particle, not on the particle’s speed

Question 76

The intensity level in decibels is defined as 10 log10(I/I0), where I0 is a reference intensity equal to the human threshold of hearing, 10–12 W/m2. What is the intensity of the threshold of pain, 120 decibels?

Answer 76

Because the intensity level is 120 dB = 10 log (I/I0), log (I/I0) must equal 12 and I/I0 must equal 1012. Therefore I = 10° W/m2, because I0 = 10-12 W/m2.

Question 77

hen a ray enters going from a lower refractive index (air) to a higher (bead) it should bend towards the

Answer 77

hen a ray enters going from a lower refractive index (air) to a higher (bead) it should bend towards the normal.

Question 78

if the object is beyond the focal length what is the nature of the image

Answer 78

real and inverted