BP/Kaplan/AAMC Physics Flashcards
A higher Reynolds number makes a fluid more likely to be
A higher Reynolds number makes a fluid more likely to be turbulent.
Increasing temperature decreases …
Increasing temperature decreases viscosity.
The Venturi effect says that when a tube narrows, the velocity …
increases and the pressure decreases. Thus, the narrow end of the tube has the lowest pressure and the larger end has the highest pressure.
The Reynolds number (which indicates the likelihood of turbulence) is directly related to …
Increasing the viscosity would therefore result in …
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.
density of water in g/cm^3
1, or 1000 kg/m^3
The law of conservation of energy states that
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.
DO U NEED the angle of incline to find work? which angle do u need? does work depend on path or no?
. 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.
For ramps, the ideal mechanical advantage can be calculated as follows:
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.
Moving a heavier box would also increase the amount of …
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.
work is…
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)
how do things move in electric field lines
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.
what does it mean if two pts are on the same equipot line?
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.
the charge gained e PE, so what does this mean? what are the units of electric potential? how can we find e potential?
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.
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
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.
what is the lorentz force and what can it also be called
The Lorentz force is the electric force plus the magnetic force experienced by a charged object – also known as the electromagnetic force.
what cant magnetic fields act on
Magnetic fields cannot act on objects with a velocity vector that is parallel to the direction of magnetic field lines.
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 …
positive charge movement. This is the same direction as current’s flow through circuitry.
can a material with a large bulk modulus be compressed and what does this mean
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
doppler effect eqn- when is the velocity of the SOURCE negative or positive?
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.
doppler effect eqn- when is the velocity of the OBSERVER negative or positive?
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.
what units are to be used for doppler eqn
use hz when doing doppler
what does the venturi effect state about liquid speeds and pressure exerted on surroudings
The Venturi effect states that when a fluid starts moving faster, it exerts LESS pressure on its surroundings.
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.
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.
specific gravity
density of the liquid / density of water
density of water (know all of these)
1000 kg/m3, 1 g/mL, 1 g/cm^3, 1kg/L
concave meniscus
goes in. happens when adhesive >cohesive
convex meniscus
rounds out. happens when adhesive<cohesive
why is water more likely to form a convex meniscus
bc it has strong cohesive interactions
what can apply a bouyant force
Any fluid can apply a buoyant force, including all gases and liquids.
what type of harmonics can there be for closed tubes
For closed tubes, there can only be odd number harmonics.
ultrasound and ultraviolet waves are, respectively
longitudinal, transverse