MCAT Physics Questions

A 2 kg ball is sliding east (without friction) down a hill that makes an angle of 30𐩑 with the horizontal. A child kicks the ball with a force of 10 N. what is the net acceleration of the kicked ball? a. (5sqrt(3))/2 m/s^2 b. 5sqrt(2) m/s^2 c. 5sqrt(3) m/s^2 d. 10sqrt(2) m/s^2

B

A patient puts on a mask with lateral openings and inhales oxygen from a tank as shown. What phenomenon causes static air to be drawn into the mask when oxygen flows? (IMAGE 75) a. Doppler effect b. Venturi effect c. Diffusion d. Dispersion

B

A ray of light in air strikes the flat surface of a liquid, resulting in a reflected ray. If the angle of reflection is known, what additional information is needed in order to determine the relative refractive index of the liquid compared to air? a. Angle of incidence b. Angle of refraction c. Refractive index of air d. Wavelength of the light

B

According to the de Broglie hypothesis, wave-particle duality extends to all particles, not just photons. The wavelength of any particle is a function of the particle's momentum p according to the equation =h/p. An electron orbiting a photon can thus be considered a standing wave that forms a closed loop around the nucleus: only modes producing integer wavelengths are permitted. What is the wavelength of the ground state, fundamental mode of the electron in this simple Bohr atom (let m_e represent the mass of the electron)? a. h^2/(4pi^2*m_e*k*e^2) b. h^2/(2m_e*k*e^2) c. h^2/(pi*m_e*k*e^2) d. 2m_e*k*e^2/(h^2)

B

An astronaut on Earth notes that in her soft drink an ice cube floats with 9/10 of its volume submerged. If she were instead in a lunar module parked on the Moon where the gravitation force is ⅙ that of Earth, the ice in the same soft drink would float: a. With more than 9/10 submerged b. With 9/10 submerged c. With 6/10 submerged d. Totally submerged

B

At a given temperature, the resistance of a wire to direct current depends only on the: a. Voltage applied across the wire b. Resistivity, length, and cross-sectional area c. Inductance, length, and cross-sectional area d. Resistivity, length, and capacitance

B

If a student repeated a calorimetry experiment by replacing the water in the calorimetry device with an ice bath at 0°C, how would the experimental results differ? a. The temperature of the water would increase to 10°C b. The temperature of the water would begin to increase at a later time c. The heat released when ice melts increases the measured temperature d. The amount of heat released from the combustion reaction would increase

B

Roughly to what height would a 5 kg stone need to be raised in order to have the same stored energy as the energy stored in a defibrillator's capacitor (400 J)? a. 4 m b. 8 m c. 16 m d. 32 m

B

Suppose a certain far-sighted person can see objects clearly no closer than 300 cm away. What is the minimum distance from a plane mirror such a person must be to see his reflection clearly? a. 75 cm b. 150 cm c. 300 cm d. 600 cm

B

Suppose that a stream of fluid flows steadily through a horizontal pipe of varying cross-sectional diameter. Neglecting viscosity, where is the fluid pressure greatest? a. At the intake point b. At the point of maximum diameter c. At the point of minimum diameter d. At the point of maximum change in diameter

B

What is the electric potential a millimeter away from a carbon atom nucleus? a. 1.4 x 10^-9 V b. 8.6 x 10^-6 V c. 1.4 x 10^-6 V d. 8.6 x 10^-3 V

B

In which of the following does sound travel most rapidly? a. Air (0°C) b. Water (10°C) c. Iron (20°C) d. Sound travels at approximately the same speed in all of the above

C

Laser Doppler vibrometers detect the Doppler shift of a laser beam reflected off an individual's chest to measure respiratory rate. The calculated displacement of the chest during a breath using a 500-nm laser is shown below. If the laser source is stationary, at which point(s) would the observed frequency of the reflected laser be 6 x 1-^14 Hz? (IMAGE 85) a. II only b. I and II only c. I and III only d. II and III only

C

Neglecting air resistance, what is the total velocity of a parachutist just before engaging his parachute, 8 s after dropping from an airplane flying horizontally at 60 m/s? a. 60 m/s b. 80 m/s c. 100 m/s d. 140 m/s

C

The first time Jeff goes up an incline of 30𐩑 at 2 m/s, what distance along the incline does the toboggan travel before it comes to rest? Jeff has a mass of 28 kg and the mass of the toboggan is 2 kg. a. 0.2 m b. 0.3 m c. 0.4 m d. 0.5 m

C

A compressor exerts a pressure of 400 Pa to compress nitrogen gas from 3 L to 1 L. If no heat transfer occurs, how much will the internal energy of the gas change? (Note 1 m^3 = 1000 L) a. 0.8 J b. 1.2 J c. 800 J d. 1200 J

A

An experiment is conducted where a cue ball (mass 0.25 kg) moves at 10 m/s toward an adjacent numbered ball (mass 0.25 kg) at rest. In Trial 1, the collision is elastic. In Trial 2, the collision is perfectly inelastic. What is the speed of the cue ball immediately after the collision in Trial 1 and Trial 2 respectively? a. 0 m/s and 5 m/s b. 0 m/s and 10 m/s c. 5 m/s and 0 m/s d. 5 m/s and 5 m/s

A

An experimental setup designed to measure the resistance of an unknown resistor R using two known resistors R1 and R2, the variable resistor R3, a voltage source, and a voltmeter is shown. Which relationship gives the value of R when R3 is adjusted so that the voltmeter reading is zero? (IMAGE 83) a. R = R3 x R1/R2 b. R = R3 + R2 - R1 c. R = R3 - R2 + R1 d. R = R3 x R2/R1

A

If the sonic boom that the jet produces when it goes supersonic is 60 dB louder than acceptable limits for the people on the base below, at minimum how many times farther away should it be from the base when it goes supersonic? a. 10^3 b. 10^4 c. 10^5 d. 10^6

A

Let X denote the horizontal distance traveled when a projectile (launched at an angle theta0 with 30° < theta0 < 60°) has attained its maximum height. If the effect of air resistance is taken into account, then which one of the following relations is correct concerning the projectile's range R? a. R/2 < X b. (Rcos(theta0))/2 > X c. (Rsin(theta0))/2 > X d. R/2 > X

A

The density of a human body can be calculated from its weight in air, Wair, and its weight while submersed in water, Ww. The density of a human body is proportional to: a. Wair/(Wair-Ww) b. (Wair-Ww)/Wair c. (Wair-Ww)/Ww d. Ww/(Wair-Ww)

A

The engine of a small and unmanned airplane produces a known and specific sound frequency (not given). A stationary sound detection device observes that the known emitted sound frequency is 90% of the perceived sound frequency. Relative to the detection device, in which direction and at what velocity is the plane moving? a. Towards the detector, at 34 m/s b. Away from the detector, at 34 m/s c. Towards the detector, at 64 m/s d. Away from the detector, at 64 m/s

A

The explanation for the fact that radioactive isotopes of an element exhibit the same chemical behavior as the stable isotopes of the element is that each has the same: a. Atomic number b. Number of neutrons c. Mass number d. Atomic weight

A

The figure shows an arrow, pointing upward, located a distance p in front of a converging lens of focal length f. If p > f as in the figure, what kind of image of the arrow is formed by the lens? (IMAGE 77) a. Real and pointing down b. Real and pointing up c. Virtual and pointing down d. Virtual and pointing up

A

The glass that is used as a beam splitter is replaced with glass that is identical except that it has a 10% higher index of refraction. Which of the following changes will occur to the pinhole image? a. It will move b. It will become larger c. It will become smaller d. It will become more clear

A

Visible light travels more slowly through an optically dense medium than through a vacuum. A possible explanation for this could be that the light: a. Is absorbed and re-emitted by the atomic structure of the optically dense medium b. Is absorbed and re-emitted by the nucleus of the material in the optically dense medium c. Bounces around randomly inside of the optically dense medium before emerging d. Loses amplitude as it passes through the optically dense medium

A

Which of the following is true of images created with optical instruments by virtual objects with negative object distances? a. Real images are always upright, and virtual images are always inverted b. Real images are always inverted, and virtual images are always upright c. Both real and virtual images are always upright d. Both real and virtual images are always inverted

A

With its carriage full, an amusement park ride goes through the top of its swing. What is the value of the normal force if its speed is 20 m/s? (Same numbers as in question 10) a. 42 kN b. 48 kN c. 54 kN d. 60 kN

A

A 100 kg bungee jumper attached to a bungee cord jumps off a bridge. The bungee cord stretches and the man reaches the lowest spot in his descent before beginning to rise. The force of the stretched bungee cord can be approximated using Hooke's law, where the value of the spring constant is replaced by an elasticity constant, in this case, 100 kg/s^2. If the cord is stretched by 30 m beyond its vertical equilibrium length at the lowest spot of the man's descent, then what was his acceleration at the lowest spot? a. 0 m/s^2 b. 10 m/s^2 c. 20 m/s^2 d. 30 m/s^2

C

A closed system consisting of a balloon expands by 5 x 10^-2 L at constant temperature in an environment with a pressure of 1.0 x 10^5 Pa. what is the value of heat transfer in this process? a. -5.0 J b. -5.0 kJ c. 5.0 J d. 5.0 kJ

C

If the blood in the body is taken to be an ideal fluid, which of the following is true of blood flow in the arteries? a. The flow speed of blood is the same through the complete peripheral vascular system at any given moment, but it varies over time b. The flow speed of blood is the same through the complete peripheral vascular system and does not vary over time c. The flow rate of blood is the same through the complete peripheral vascular system at any given moment, but it varies over time d. The flow rate of blood is the same through the complete peripheral vascular system and does not vary over time

C

In an amusement park ride, when the floor drops down and away, the passengers feel pushed up against the wall. Which of the following best explains this phenomenon? a. The passengers experience a centrifugal force due to the rotation of the ride b. The passengers experience a centripetal force due to the circular configuration of the ride c. The passengers experience linear inertia that is opposed by the rotation of the ride d. The passengers experience rotational inertia that is opposed by the rotation of the ride

C

In modern radiotherapy, superconducting wire coils are used to create magnetic fields that focus particle beams in order to deliver the maximum dose of ionizing radiation to a tumor site while minimizing the destruction of healthy tissue. For which of the following types of radiation would this technique NOT be useful? a. Alpha particles b. Proton beams c. Gamma photons d. Beta particles

C

Uniform magnetic fields created by advanced medical imaging devices most likely come from the: a. Nuclear decay of device materials b. Electric forces gendered by charged particles c. Motion of electrons along a circular pathway d. Storage of electrical charges at small distances

C

What is the tangential speed required to suspend a 50 kg man in an amusement park ride with r = 4 m and coefficient of static friction = 0.50? a. 7 m/s b. 8 m/s c. 9 m/s d. 10 m/s

C

When spinning a coin on a flat surface, two equal forces with opposite directions are applied to the opposite sides of a coin. Which of the following is true about the coin after it leaves the hand? (Assume ideal frictionless motion) a. The coin does not rotate because equal but opposite forces cancel each other out b. The coin does not rotate because equal but opposite torques cancel each other out c. The coin rotates and the rotational acceleration is zero d. The coin rotates and the rotational acceleration is equal to the nonzero net torque divided by the moment of inertia

C

Which of the following best describes the negative charge on a metal marble? a. The negative charge means the electric field inside the marble points in, toward the center of the marble b. The negative charge means the electric field inside the marble points out, away from the center of the marble c. There is no electric field inside the marble since the negative charge is spread evenly on the surface of the marble d. There is no electric field inside the marble since conductors absorb charge and neutralize it

C

A 0.5-kg uniform meter stick is suspended by a single string at the 30-cm mark. A 0.2-kg mass hangs at the 80 cm mark. What mass hung at the 10-cm mark will produce equilibrium? a. 0.3 kg b. 0.5 kg c. 0.7 kg d. 1.0 kg

D

A 100 g block is sitting at rest on a horizontal table. According to Newton's third law, which of the following incidactes the correct action-reaction pair of the two forces? a. The gravitational force exerted by the table on the block and the normal force exerted by the block on the table b. The gravitational force exerted by the block on Earth and the normal force exerted by the table on the block c. The weight of the block and the normal force exerted by the table on the block d. The weight of the block and the gravitational force exerted by the block on the Earth

D

A person is pulling a block of mass m with a force equal to its weight directed 30𐩑 above the horizontal plane across a rough surface, generating a friction f on the block. If the person is now pushing downward on the block with the same force 30𐩑 below the horizontal plane across the same rough surface, what is the friction on the block? (uk is the coefficient of kinetic friction across the surface). a. f b. 1.5f c. 2f d. 3f

D

After a block began to slide, how did its speed vary with time? (Note: assume that the tension and kinetic friction forces on the block were constant in magnitude) a. It was constant in time b. It increased exponentially with time c. It was first constant, then increased linearly with time d. It increased linearly with time

D

An atom, whose momentum has magnitude p and whose velocity vector is perpendicular to an infinitely heavy wall, strikes the wall and recoils elastically. What is the magnitude of the change in the atom's momentum? a. 0 b. p/2 c. p d. 2p

D

An object is thrown with an initial speed of 7m/s directed 45𐩑 above the horizontal from a cliff. After reaching the peak of its trajectory, it falls 20 m to the ground below. What is the approximate ratio of the time it takes to hit the ground from the peak of the trajectory to the time it takes from its release to the peak of the trajectory? a. 0.5 b. 1 c. 2 d. 4

D

Electric power for transmission over long distances is "stepped up" to a very high voltage in order: a. To produce currents of higher density b. To produce higher currents in the transmission wires c. To make less insulation necessary d. To cut down the heat loss in the transmission wires

D

How much work is needed to lift a box of mass 2 kg up a height of 3 m using a pulley system with 75% efficiency? a. 4 J b. 8 J c. 45 J d. 80 J

D

If the second floor and the top floor of a building are separated by a distance of 100 m, what is the approximate difference between the air pressures of the two levels? (Note: air density = 1.2 kg/m^3. Neglect the compressibility of air) a. 600 N/m^2 b. 800 N/m^2 c. 1000 N/m^2 d. 1200 N/m^2

D

Imagine a lithium atom where the two electrons in the first energy level are at exact opposite sides of the nucleus and the electron in the second energy level is in line with the other electrons so that the three electrons and the nucleus all lie on a straight line. How much work would you need to apply to remove the outermost electron if the atomic radius is 100 pm and the distance between the first and second energy level is 50 pm? a. (ke/150) x 10^12 J b. (ke^2/150) x 10^12 J c. (ke/300) x 10^12 J d. (ke^2/300) x 10^12 J

D

In a healthy person standing at rest, a comparison of arterial blood pressure measured in the arm with that measured in the leg shows that the pressure in the leg is: a. Lower, because the blood flow rate is less b. Lower, because viscous flow resistance causes pressure loss c. The same, because viscous pressure loss precisely compensates the hydrostatic pressure increase d. Greater, because the column of blood between the arm and the leg has a hydrostatic pressure

D

Making which of the following changes to a circuit element will increase the capacitance of a capacitor? a. Replacing a 500-Ω resistor with a 250-Ω resistor b. Replacing the 10-V battery with a 20-V battery c. Increasing the separation of the capacitor plates d. Increasing the area of the capacitor plates

D

Which of the following energy conversions best describes what takes place in a battery-powered resistive circuit when the current is flowing? a. Electric to thermal to chemical b. Chemical to thermal to electric c. Electric to chemical to thermal d. Chemical to electric to thermal

D

Why must a person sitting on a chair either lean forward or slide their feet under the chair in order to stand up? a. To increase the force required to stand up b. To use the friction with the ground c. To reduce the energy required to stand up d. To keep the body in equilibrium while rising

D