Prepare for the MCAT Physics section with these AAMC question pack practice questions and answers. This guide covers mechanics, electricity, magnetism, optics, and thermodynamics.
Q: if you are given voltage between two plates, and the distance between the plates, how do you find the magnitude of the electric field between them
Answer: (voltage)/(distance)
Q: what wave difference causes destructive interference
Answer: half of a wave length/180 degrees
Q: what is the doppler equation for frequency
Answer: Δf/f = -v/c
Q: what is the difference between constructive and destructive interference of waves
Answer: constructive interference occurs when the waves are identical/very close to being in phase and create a wave with a larger amplitudedestructive occurs when one wave is half of a wavelength shifted (180 degrees out of phase) and they cancel out to 0
Q: according to the doppler effect, if the source of a frequency is moving away from an observer, how does the perceived frequency change? what about if the source if moving toward an observer?
Answer: if the source emitting a frequency is moving toward an observer – the observed frequency is highreif the source is moving away from an observer – the observed frequency is lower
Q: how is the magnitude of the change in frequency related to the speed of a wave
Answer: inversely proportionalif the speed of a wave is slower, the change in the frequency is greater
Q: how does changing the gravity that an object experiences affect the amount that it will be submerged in a fluid
Answer: it does not change itweight=mg=(rho)gVg cancels out
Q: how does changing the distance between cathode plates effect the electric field created between them
Answer: increasing the distance between the plates decreases the electric field(more than decreasing the voltage would decrease the electric field)
Q: how do charged particles behave in an electric field
Answer: they ACCELERATE toward the opposite charged area
Q: why does light slow down when entering a more dense medium
Answer: the light is absorbed and re-emitted by the optically dense medium
Q: what is the only thing the focal length of a mirror depends on
Answer: radius of curvature
Q: what happens to velocity in projectile motion as it reaches its peak
Answer: velocity decreases to 0 when it reaches the peak
Q: how does n change for two consecutive wavelengths/resonances in a closed pipe
Answer: n->n+2
Q: how are batteries and capacitors related in a circuit
Answer: the charge that the battery holds (in V) is the charge that capacitor can charge to
Q: what happens to the nucleus in beta decay
Answer: a neutron converts to a proton while emitting an electron(atomic number increases by 1)
Q: when tension is being applied to a block at an angle, how do you find the tension (force) in the X and Y (horizontal and vertical) directions
Answer: X/horizontal: T(cosΘ)Y/vertical: T(sinΘ)
Q: what property of a light wave changes when it enters into a medium with a different index of refraction
Answer: wavelength – speed increases due to change in wavelengthfrequency does NOT change
Q: what is true about the orientation of real/virtual images created by single lenses/mirrors
Answer: real images are always invertedvirtual images are always upright
Q: what is the relationship between the angle of reflection and the angle of incidence
Answer: angle of incidence = angle of reflectionNOT refraction
Q: when doing inclined plane questions, how do you separate the parallel and perpendicular components (to the inclined plane)
Answer: (usually have to do for gravity)parallel is mgsinΘperpendicular is mgcosΘ
Q: how do you calculate work for simple machines (ie pulleys)
Answer: W=mghdo not need to include angles
Q: how do you calculate the magnitude of the electric field of a point charge
Answer: E=kq/r^2 or E=Fe/q (force of electric field/charge)
Q: when solving for the volume of a submerged object, how do you rearrange the archimedes principle equation
Answer: (pfluid)(Vfluid displaced) g = (pobject)(Vobject)(g)Vfluid = VsubmergedVs/Vo=Po/Pf
Q: how can you find the volume of something submerged in WATER using specific gravity
Answer: SGobject/SGwater = percent submerged
Q: how is the specific gravity of the object related to whether it will float/sink in water
Answer: if SG of object is less than 1 it will floatif SG of object is greater than 1 it will sinkif SG of object is exactly 1 it will be submerged but not sink
Q: when you have a tube with fluid flowing through it, what happens to the pressure when the tube narrows
Answer: if the tube narrows, velocity increases, so pressure has to decreases (Bernouli’s)
Q: how do you calculate flow rate of a fluid
Answer: flow rate = speed (cross sectional area)cross sectional area is πr^2
Q: in what direction does a magnetic force act on a moving particle
Answer: perpendicular to the direction of the moving particle
Q: in what direction does a magnetic force act on a magnetic field
Answer: perpendicular to the direction of the magnetic field
Q: how does acceleration change when a constant force is applied to a block
Answer: constant force = constant acceleration = linear increase in speed
Q: if the force of gravity is decreased, how does that affect the time it takes for a projectile object to return to the ground
Answer: it increases the time it takes by an inversely proportional factor that the gravity was decreased byex) gravity goes from g->g/6 now time to reach ground is 6t
Q: how does frequency change when traveling through different media
Answer: frequency does not change in different media, only wavelength changes
Q: how does wavelength change when speed of the sound wave changes
Answer: speed and wavelength are directly proportional – if speed doubles wavelength doubles
Q: what properties of sound waves change when traveling through different media
Answer: wavelength and speed
Q: why does the intensity of sound change when a wall is placed between the sound and the observer
Answer: some of the sound wave is reflected/absorbed by the solid wall which decreases the intensity
Q: how do you solve torque equilibrium problems if the fulcrum is not at the center of mass
Answer: you have to take into account the torque of the actual object at the center of massex) if 5kg 10m stick suspended at 4m from the left, then on the right there is the torque of what ever is hanging on it AND the torque of the stick which is (5kg)(1m) where the 1m is how far away the center of mass is from the suspension point/fulcrum
Q: what is the relationship between work and energy
Answer: energy = workwork is F x d (Nm) and Nm = J
Q: kinematic equations
Answer: V=Vo+atX=Vot+(1/2)at^2V^2=Vo^2 + 2axx = (V+Vo)/2 +t