MCAT Physics and Math Review Discrete Practice Questions

B. 20 m

1.1 A man walks 30 m east and then 40 m north. What is the difference between his traveled distance and his displacement? A. 0 m B. 20 m C. 50 m D. 70 m

D. Distance

1.10 Which of the following quantities is NOT a vector? A. Velocity B. Force C. Displacement D. Distance

B. 67 cm from the fulcrum

1.11 A 30 kg girl sits on a seesaw at a distance of 2 m from the fulcrum. Where must her father sit to balance the seesaw if he has a mass of 90 kg? A. 67 cm from the girl B. 67 cm from the fulcrum C. 133 cm from the girl D. 267 cm from the fulcrum

B. 6 m/s

1.12 A BASE jumper runs off a cliff with a speed of 3 m/s. Which of the following is closest to his speed after 0.5 seconds? A. 3 m/s B. 6 m/s C. 8 m/s D. 10 m/s

C. the ball will reach the ground first.

1.13 A rock (m = 2 kg) is shot up vertically at the same time that a ball (m = 0.5 kg) is projected horizontally. If both start from the same height: A. the rock and ball will reach the ground at the same time. B. the rock will reach the ground first. C. the ball will reach the ground first. D. the rock and ball will collide in the air before reaching the ground.

C. Centrifugal force always acts antiparallel to the centripetal force vector.

1.14 Centrifugal force is an apparent outward force during circular motion. It has been described as a reaction force according to Newton's third law. Which of the following statements is most likely to be correct regarding centrifugal force? A. Centrifugal force exists only for uniform circular motion, not nonuniform circular motion. B. Centrifugal force exists only when tension or a normal force provides centripetal acceleration. C. Centrifugal force always acts antiparallel to the centripetal force vector. D. Centrifugal force is result of repulsive electrostatic interactions.

B. II only

1.15 Which of the following statements is true of movement on a plane with friction? I. Acceleration is a function of applied force only. II. More force is needed to accelerate a stationary object than an identical moving object. III. The force of friction is independent of the mass of objects. A. I only B. II only C. I and II only D. I and III only

A. 160 m/s

1.2 A 1000 kg rocket ship, travelling at 100 m/s, is acted upon by an average force of 20 kN applied in the direction of its motion for 8 s. What is the change in velocity of the rocket? A. 160 m/s B. 260 m/s C. 160,000 m/s D. 260,000 m/s

C. 24,000 km/hr^2

1.3 A car is travelling at 40 km/hr and the driver puts on the brakes, bringing the car to rest in a time of 6 s. What is the magnitude of the average acceleration of the car? A. 240 km/hr^2 B. 12,000 km/hr^2 C. 24,000 km/hr^2 D. 30,000 km/hr^2

A. The tension is greater than 9800 N.

1.4 An elevator is designed to carry a maximum weight of 9800 N (including its own weight), and to move upward at a speed of 5 m/s after an initial period of acceleration. What is the relationship between the maximum tension in the elevator cable and the maximum weight of the elevator while the elevator is accelerating upward? A. The tension is greater than 9800 N. B. The tension is less than 9800 N. C. The tension equals 9800 N. D. It cannot be determined from the information given.

A. The first object has a greater change in speed.

1.5 At a place where g = 9.8 m/s^2, an object is thrown vertically downward with a speed of 5 m/s while a different object is thrown vertically upward with a speed of 10 m/s. Which object undergoes a greater change in speed in a time of 2 s? A. The first object has a greater change in speed. B. The second object has a greater change in speed. C. Both objects undergo the same change in speed. D. It cannot be determined from the information given.

A. The instant he jumps.

1.6 A firefighter jumps horizontally form a burning building with an initial speed of 1.5 m/s. At what time is the angle between his velocity and acceleration vectors the greatest? A. The instant he jumps. B. When he reaches terminal velocity. C. Halfway through his fall. D. Right before he lands on the ground.

B. 49 N

1.7 A 10 kg wagon rests on an inclined plane. The plane makes an angle of 30 degrees with the horizontal. Approximately how large is the force required to keep the wagon from sliding down the plane (Note: sin 30 degrees = 0.5, cos 30 degrees = 0.866)? A. 10 N B. 49 N C. 85 N D. 98 N

C. kg x m/s = (kg x m)/s^2 x s

1.8 Which of the following expressions correctly illustrates the SI base units for each of the variables in the formula below? A. lb x mph = ft x lb x s B. kg x m/s = N x s C. kg x m/s = (kg x m)/s^2 x s D. g x m/s = (g x m)/s^2 x s

B. The frictional force decreases.

1.9 A 20 kg wagon is released from rest from the top of a 15 m long lane, which is angled at 30 degrees with the horizontal. Assuming that there is friction between the ramp and the wagon, how is this frictional force affected if the angle of the incline is increased? A. The frictional force increases. B. The frictional force decreases. C. The frictional force remains the same. D. It cannot be determined from the information given.

C. 6468 J and 0 J, respectively

2.1 A weight lifter lifts a 275 kg barbell from the ground to a height of 2.4 m. How much work has he done in lifting the barbell, and how much work is required to hold the weight at that height? A. 3234 J and 0 J, respectively B. 3234 J and 3234 J, respectively C. 6468 J and 0 J, respectively D. 6468 J and 6468 J, respectively

D. The potential energy has quadrupled.

2.10 A massless spring initially compressed by a displacement of two centimeters is now compressed by four centimeters. How has the potential energy of this system changed? A. The potential energy has not changed. B. The potential energy has doubled. C. The potential energy has increased by two joules. D. The potential energy has quadrupled.

A. Sarah will bounce higher than Josh.

2.11 Josh, who has a mass of 80 kg, and Sarah, who has a mass of 50 kg, jump off a 20 m tall building and land on a fire net. The net compresses, and they bounce back up at the same time. Which of the following statements is NOT true? A. Sarah will bounce higher than Josh. B. For Josh, the change in speed from the start of the jump to contacting the net is 20 m/s. C. Josh will experience a greater force upon impact than Sarah. D. The energy in this event is converted from potential to kinetic to elastic to kinetic.

B. I and III only

2.12 A parachutist jumps from a plane. Beginning at the point when she reaches terminal velocity (constant velocity during freefall), which of the following is/are true? I. The jumper is in translational equilibrium. II. The jumper is not being acted upon by any forces. III. There is an equal amount of work being done by gravity and air resistance. A. I only B. I and III only C. II and III only D. I, II, and III

B. Mechanical advantage compares values of forces; efficiency compares values of work.

2.13 Mechanical advantage and efficiency are both ratios. Which of the following is true regarding the quantities used in these ratios? A. Mechanical advantage compares values of work; efficiency compares values of power. B. Mechanical advantage compares values of forces; efficiency compares values of work. C. Mechanical advantage compares values of power; efficiency compares values of energy. D. Mechanical advantage compares values of work; efficiency compares values of forces.

C. The kinetic energy has decreased by the same quantity as the potential energy has increased.

2.14 If the gravitational potential energy of an object has doubled in the absence of nonconservative forces, which of the following must be true, assuming the total mechanical energy of the object is constant? A. The object has been lifted to twice its initial height. B. The kinetic energy of the object has been halved. C. The kinetic energy has decreased by the same quantity as the potential energy has increased. D. The mass of the object has doubled.

A. Car A and Car B both have unlimited velocities.

2.15 A consumer is comparing two new cars. Car A exerts 250 horsepower, while Car B exerts 300 horsepower. The consumer is most concerned about the peak velocity that the car can reach. If nonconservative forces can be ignored, which of the following statements is true? (Note: 1 horsepower = 745.7 W) A. Car A and Car B both have unlimited velocities. B. Car A will reach its peak velocity more quickly than Car B. C. Car A will dissipate less energy to the surroundings than Car B. D. Car A will have a lower peak velocity than Car B.

C. 433 kJ

2.2 A tractor pulls a log with a mass of 500 kg along the ground for 100 m. The rope (between the tractor and the log) makes an angle of 30 degrees with the ground and is acted on by a tensile force of 5000 N. How much work does the tractor perform in this scenario? (Note: sin 30 degrees = 0.5, cos 30 degrees = 0.866, tan 30 degrees = 0.577) A. 250 kJ B. 289 kJ C. 433 kJ D. 500 kJ

B. 150 kW

2.3 A 2000 kg experimental car can accelerate from 0 to 30 m/s in 6 s. What is the average power of the engine needed to achieve this acceleration? A. 150 W B. 150 kW C. 900 W D. 900kW

D. 2000 J

2.4 A 40 kg block is resting at a height of 5 m off the ground. If the block is released and falls to the ground, which of the following is closest to its total mechanical energy at a height of 2 m, assuming negligible air resistance? A. 0 J B. 400 J C. 800 J D. 2000 J

C. 0 J

2.5 5 m^3 of a gas are brought from an initial pressure of 1 kPa to a pressure of 3 kPa through an isochoric process. During this process, the work performed by the gas is: A. -10 kJ B. -10 J C. 0 J D. +10 kJ

B. 60 N

2.6 In the pulley system shown below, which of the following is closest to the tension force in each rope if the mass of the object is 10 kg and the object is accelerating upwards at 2 m/s^2? A. 50 N B. 60 N C. 100 N D. 120 N

c. Gravity

2.7 Which of the following is a conservative force? A. Air resistance B. Friction C. Gravity D. Convection

A. No work is done.

2.8 During uniform circular motion, which of the following relationships is necessarily true? A. No work is done. B. The centripetal force does work. C. The velocity does work. D. Potential energy depends on position of the object around the circle.

B. The total work done on any object is equal to the change in kinetic energy for that object.

2.9 Which of the following best characterizes the work-energy theorem? A. The work done by any force is proportional only to the magnitude of that force. B. The total work done on any object is equal to the change in kinetic energy for that object. C. The work done on an object by any force is proportional to the change in kinetic energy for that object. D. The work done by an applied force on an object is equal to the change in kinetic energy of that object.

C. 18 degrees Fahrenheit

3.1 If an object with an initial temperature of 300 K increases its temperature by 1 degree Celsius every minute, by how many degrees Fahrenheit will its temperature have increased in 10 minutes? A. 6 degrees Fahrenheit B. 10 degrees Fahrenheit C. 18 degrees Fahrenheit D. 30 degrees Celsius

A. More than 1 J

3.10 A certain substance has a specific heat of 1 J/ (mol x K) and a melting point of 350 K. If one mole of the substance is currently at a temperature of 349 K, how much energy must be added in order to melt it? A. More than 1 J B. Exactly 1 J C. Less than 1 J but more than 0 J D. Less than 0 J

B. Heat

3.11 Which of the following is NOT a state function? A. Internal energy B. Heat C. Temperature D. Entropy

C. Conduction

3.12 The figure shown depicts a thick metal container with two compartments. Compartment A is full of hot gas, while compartment B is full of cold gas. What is the primary mode of heat transfer in this system? A. Radiation B. Convection C. Conduction D. Enthalpy

D. Substance B has a higher internal energy.

3.13 Substances A and B have the same freezing and boiling points. If solid samples of both substances are heated in the exact same way, substance A boils before substance B. Which of the following would NOT explain this phenomenon? A. Substance B has a higher specific heat. B. Substance B has a higher heat of vaporization. C. Substance B has a higher heat of fusion. D. Substance B has a higher internal energy.

B. positive in experiment A and zero in experiment B.

3.14 In experiment A, a student mixes ink with water and notices that the two liquids mix evenly. In experiment B, the student mixes oil with water; in this case, the liquids separate into two different layers. The entropy change is: A. positive in experiment A and negative in experiment B. B. positive in experiment A and zero in experiment B. C. negative in experiment A and positive in experiment B. D. zero in experiment A and negative in experiment B.

C. A boiling liquid is heated on a hot plate.

3.15 Which of the following processes is LEAST likely to be accompanied by a change in temperature? A. The kinetic energy of a gas is increased through a chemical reaction. B. Energy is transferred to a solid via electromagnetic waves. C. A boiling liquid is heated on a hot plate. D. A warm gas is mixed with a cold gas.

A. I. Radiation II. Conduction III. Convection

3.2 Which of the following choices correctly identifies the following three heat transfer processes? I. Heat transferred from the Sun to the Earth. II. A metal spoon heating up when placed in a pot of hot soup. III. A rising plume of smoke from a fire. A. I. Radiation II. Conduction III. Convection B. I. Conduction II. Radiation III. Convection C. I. Radiation II. Convection III. Conduction D. I. Convection II. Conduction III. Radiation

C. No, because it expands by 2.2 cm

3.3 A 20 m steel rod at 10 degrees Celsius is dangling from the edge of a building and is 2.5 cm from the ground. If the rod is heated to 110 degrees Celsius, will the rod touch the ground? (Note: alpha = 1.1 x 10^-5 K^-1) A. Yes, because it expands by 3.2 cm B. Yes, because it expands by 2.6 cm C. No, because it expands by 2.2 cm D. No, because it expands by 1.8 cm

C. 60 degrees Celsius

3.4 What is the final temperature of a 3 kg wrought iron fireplace tool that is left in front of an electric heater, absorbing heat energy at a rate of 100 W for 10 minutes? Assume the pendant is initially at 20 degrees Celsius and that the specific heat of wrought iron is 500 J/(kg x K). A. 40 degrees Celsius B. 50 degrees Celsius C. 60 degrees Celsius D. 70 degrees Celsius

D. 97 kJ

3.5 How much heat is required to completely melt 500 g gold earrings, given that their initial temperature is 25 degrees Celsius? (The melting point of gold is 1064 degrees Celsius, its heat of fusion is 6.37 x 10^4 J/kg, and its specific heat is 126 J/(kg x K). A. 15 kJ B. 32 kJ C. 66 kJ D. 97 kJ

C. 7.5 J

3.6 Given the cycle shown, what is the total work done by the gas during the cycle? A. -10 J B. 0 J C. 7.5 J D. 17.5 J

B. Increases because the work done on the gas is positive.

3.7 In an adiabatic compression process, the internal energy of the gas: A. Increases because the work done on the gas is negative. B. Increases because the work done on the gas is positive. C. decreases because the work done on the gas is negative. D. decreases because the work done on the gas is positive.

B. decrease when the entropy of the surroundings increases by at least as much.

3.8 The entropy of a system can: A. never decrease. B. decrease when the entropy of the surroundings increases by at least as much. C. decrease when the system is isolated and the process is irreversible. D. decrease during an adiabatic reversible process.

A. She was trying to create an isolated system but created an open system instead.

3.9 A student making a coffee cup calorimeter fails to use a second coffee cup and inadequately seals the lid. What was her initial goal, and what was the result of this mistake? A. She was trying to create an isolated system but created an open system instead. B. She was trying to create an isolated system but created a closed system instead. C. She was trying to create a closed system but created an open system instead. D. She was trying to create a closed system but created an isolated system instead.

C. 3 atm

4.1 Objects A and B are submerged at a depth of 1 m in a liquid with a specific gravity of 0.877. Given that the density of object B is one-third that of object A and that the gauge pressure of object A is 3 atm, what is the gauge pressure of object B? (Note: Assume atmospheric pressure is 1 atm and g = 9.8 m/s^2.) A. 1 atm B. 2 atm C. 3 atm D. 9 atm

B. 16 N

4.10 A hydraulic system is designed to allow water levels to change depending on a force applied at the top of the tank as shown. If a force, F1, of 4 N is applied to a square flexible cover where A1 = 16, and the area A2 = 64, what force must be applied to A2 to keep the water levels from changing? A. 4 N B. 16 N C. 32 N D. No force needs to be applied.

A. Ball A

4.11 Balls A and B of equal mass (shown below) are fully submerged in a swimming pool. Which ball will produce the greater buoyant force? A. Ball A B. Ball B C. The forces will be equal. D. It is impossible to know without knowing the exact volume of each ball.

B. The speed of airflow is greater over the curved top of the wing, resulting in less pressure on the top of the wing and the production of a net upward force on the wing, in turn resulting in flight.

4.12 Bernoulli's equation is the reason for the upward force that permits airplane flight. Which statement best summarizes the equation's relationship to flight? A. The speed of airflow is equal on the top and bottom of a wing, resulting in nonturbulent flight. B. The speed of airflow is greater over the curved top of the wing, resulting in less pressure on the top of the wing and the production of a net upward force on the wing, in turn resulting in flight. C. The speed of airflow on the flat bottom of the wing is greater than over the curved top of the wing, resulting in more pressure below the wing and the production of a net upward force on the wing, in turn resulting in flight. D. The weight of the wing is directly proportional to the weight of the air it displaces.

A. 1%

4.13 A low-pressure weather system can decrease the atmospheric pressure from 1 atm to 0.99 atm. By what percent will this decrease the force on a rectangular window from the outside? (Note: Assume the window is 6 m by 3 m and the glass is 3 cm thick.) A. 1% B. 10% C. 1/3% D. 30%

C. Whenever the depth of fluid A is 2 times that of fluid B

4.14 Two fluids, A and B, have densities of x and 2x, respectivley. They are tested independently to assess absolute pressure at varying depths. At what depths will the pressure below the surface of these two fluids be equal? A. Whenever the depth of fluid A is one-half that of fluid B B. Whenever the depth of fluid A equals that of fluid B C. Whenever the depth of fluid A is 2 times that of fluid B D. Whenever the depth of the fluid A is 4 times that of fluid B.

B. Decrease the speed

4.15 A water tower operator is interested in increasing the pressure of a column of water that is applied to a piston. She hopes that increasing the pressure will increase the force being applied to the piston. The only way to increase the pressure is to alter the speed of the water as it flows through the pipe to the piston. How should the speed of the water be changed to increase the pressure and force? A. Increase the speed B. Decrease the speed C. Release water intermittently against the pipe D. The speed of water will not change pressure at the piston.

B. 724 N

4.2 An anchor made of iron weighs 833 N on the deck of a ship. If the anchor is now suspended in seawater by a massless chain, what is the tension in the chain? (Note: The density of iron is 7800 kg/m^3 and the density of seawater is 1025 kg/m^3.) A. 100 N B. 724 N C. 833 N D. 957 N

A. Ball A has the greater acceleration.

4.3 Two wooden balls of equal volume but different density are held beneath the surface of a container of water. Ball A has a density of 0.5 g/cm^3, and ball B has a density of 0.7 g/cm^3. When the balls are released, they will accelerate upward to the surface. What is the relationship between the acceleration of ball A and that of ball B? A. Ball A has the greater acceleration. B. Ball B has the greater acceleration. C. Balls A and B have the same acceleration. D. It cannot be determined from information given.

C. 4.5 m/s

4.4 Water flows from a pipe of diameter 0.15 m into one of diameter 0.2 m. If the speed in the 0.15 m pipe is 8 m/s, what is the speed in the 0.2 m pipe? A. 3 m/s B. 3.7 m/s C. 4.5 m/s D. 6 m/s

A. The cross-sectional area must be doubled.

4.5 A hydraulic lever is used to lift a heavy hospital bed, requiring an amount of work W. When the same bed with a patient is lifted, the work required is doubled. How can the cross-sectional area of the platform on which the bed is lifted be changed so that the pressure on the hydraulic lever remains constant? A. The cross-sectional area must be doubled. B. The cross-sectional area must be halved. C. The cross-sectional area must be divided by four. D. The cross-sectional area must remain constant.

B. Pipe 2

4.6 The figure shown represents a section through a horizontal pipe of varying diameters into which four open vertical pipes connect. If water is allowed to flow through the pipe in the direction indicated, in which of the vertical pipes will the water level be lowest? A. Pipe 1 B. Pipe 2 C. Pipe 3 D. Pipe 4

C. The cross-sectional area of all the capillaries added together is much greater than the cross-sectional area of the aorta.

4.7 The speed of blood in the aorta is much higher than the speed of blood through a capillary bed. How can this fact be explained using the continuity equation, assuming that we are interested in average flow and that there is no net fluid loss? A. The aorta is located higher than the capillary bed. B. The pressure in the aorta is the same as the pressure in the capillary bed. C. The cross-sectional area of all the capillaries added together is much greater than the cross-sectional area of the aorta. D. The cross-sectional area of a capillary is much smaller than the cross-sectional area of the aorta.

C. The radius of the pipe, pressure gradient, viscosity, and length of the pipe

4.8 Which of the following data sets is sufficient to determine the linear speed through an area of a rigid pipe? A. The cross-sectional area in another segment of pipe and the cross-sectional area in the region of interest B. The Reynolds number, viscosity of the fluid, density, and diameter of the pipe C. The radius of the pipe, pressure gradient, viscosity, and length of the pipe D. The absolute pressure and density

B. 3:4

4.9 A large cylinder is filled with equal volumes of two immiscible fluids. A balloon is submerged in the first fluid; the gauge pressure in the balloon at the deepest point in the first fluid is found to be 3 atm. Next, the balloon is lowered all the way to the bottom of the second fluid, where the hydrostatic pressure in the balloon reads 8 atm. What is the ratio of the gauge pressure accounted for by the first fluid to the gauge pressure accounted for by the second fluid? A. 1:3 B. 3:4 C. 3:5 D. 3:8

B flat major

5.1 In the figure, the magnitude of the electric force on R due to S is: A. F/2 B. F C. 2F D. 4F

D. 2

5.10 An electron is accelerated over a distance d by an electric potential V. The electric potential applied to this electron is then increased over the same distance d. The speed of the electron at the end of the second trial will be larger than at the end of the first trial by a factor of: A. 16 B. 8 C. 4 D. 2

D.

5.11 Which of the following accurately depicts the field lines created by a proton that is moving toward the right on this page? A. B. C. D.

C. 18 J

5.12 A certain 9 V battery is used as a power source to move a 2 C charge. How much work is done by the battery? A. 4.5 J B. 9 J C. 18 J D. 36 J

C. F

5.13 A proton and an alpha particle (a helium nucleus) repel each other with a force of F while they are 20 nm apart. If each particle combines with three electrons, what is the magnitude of the new force between them? A. 9 F B. 3 F C. F D. F/9

B. Out of the page

5.14 A moving negative charge placed in an external magnetic field circulates counterclockwise in the plane of the paper. In which direction is the magnetic field pointing? A. Into the page B. Out of the page C. Toward the center of the circle D. Tangent to the circle

C. It experiences no rotational or linear movement.

5.15 A dipole is placed in an electric field and is allowed to come to equilibrium. How would the dipole react if the direction of the electric field is suddenly reversed? A. It rotates to align with the new field. B. It accelerates linearly along three field lines. C. It experiences no rotational or linear movement. D. It both rotates to align with the new field and accelerates linearly along the field lines.

D. 4F

5.2 If the distance between the centers of the spheres is halved, the magnitude of the force on S due to R will be: A. F/2 B. F/4 C. 2F D. 4F

B. Toward S

5.3 Assume the direction of F is the same direction as the electric field between R and S. If an electron were placed midway between R and S, the resultant electric force on the electron would be: A. Toward R B. Toward S C. Upward in the plane of the page D. Downward in the plane of the page

B. 36:9:4

5.4 If the electric field at a distance r away from charge Q is 36 N/C, what is the ratio of the electric field at r, 2r, and 3r? A. 9:3:1 B. 36:9:4 C. 36:18:9 D. 36:18:12

C. Toward the +Q charge at point A, and toward the right at point B.

5.5 A positive charge of +Q is fixed at point R a distance d away from another positive charge of +2Q fixed at point S. Point A is located midway between the charges, and point B is a distance d/2 from +2Q, as shown below. In which direction will a positive charge move if placed at point A and point B, respectively? A. Toward the +Q charge for both. B. Toward the +2Q charge for both. C. Toward the +Q charge at point A, and toward the right at point B. D. Toward the +2Q charge at point A, and toward the right at point B.

C. 2.4 x 10^-5 J

5.6 Two parallel conducting plates are separated by a distance d. One plate carries a charge +Q and the other carries a charge -Q. The voltage between the plates is 12 V. If a +2 microC charge is released from rest at the positive plate, how much kinetic energy does it have when it reaches the negative plate? A. 2.4 x 10^-6 J B. 4.8 x 10^-6 J C. 2.4 x 10^-5 J D. 4.8 x 10^-5 J

C. 0 J

5.7 The negative charge in the figure below (-1 microC) moves from y = -5 to y = +5 and Is made to follow the dashed line. What is the work required to move the negative charge along this dashed line? A. -10 J B. -5 J C. 0 J D. 10 J

C. 20 T

5.8 If the magnetic field a distance r away from a current-carrying wire is 10 T, what will be the net magnetic field at r if another wire is placed a distance 2r from the original wire (with r in the middle) and has a current twice as strong flowing in the opposite direction? A. 0 T B. 15 T C. 20 T D. 30 T

B. Anywhere on the perpendicular bisector of the dipole axis and at infinity.

5.9 Given an electric dipole, the electric potential is zero: A. Only at the midpoint of the dipole axis. B. Anywhere on the perpendicular bisector of the dipole axis and at infinity. C. Anywhere on the dipole axis. D. Only for points at infinity.

B. 1.5 C

6.1 If a defibrillator passes 15 A of current through a patient's body for 0.1 seconds, how much charge goes through the patient's skin? A. 0.15 C B. 1.5 C C. 15 C D. 150 C

C. 1.1 x 10^-1 C

6.10 The energy stored in a fully charged capacitor is given by U = 1/2 CV^2. In a typical cardiac defibrillator, a capacitor charged to 7500 V has a stored energy of 400 J. Based on this information, what is the charge on the capacitor in the cardiac defibrillator? A. 1.1 x 10^-5 C B. 5 x 10^-2 C C. 1.1 x 10^-1 C D. 3.1 x 10^6 C

C. 120 J

6.11 A 10 ohm resistor carries a current that varies as a function of time as shown. How much energy has been dissipated by the resistor after 5 s? A. 40 J B. 50 J C. 120 J D. 160 J

A. 2 A, toward x

6.12 In the figure below, six currents meet at point P. What is the magnitude and direction of the current between points P and x? A. 2 A, toward x B. 2 A, toward P C. 10 A, toward x D. 10 A, toward P

D. Adding an extra battery to the system

6.13 Which of the following will most likely increase the electric field between the plates of a parallel plate capacitor? A. Adding a resistor that is connected to the capacitor in series. B. Adding a resistor that is connected to the capacitor in parallel. C. Increasing the distance between the plates D. Adding an extra battery to the system

D. 3 ohms

6.14 Each of the resistors shown carries an individual resistance of 4 ohms. Assuming negligible resistance in the wire, what is the overall resistance of the circuit? A. 16 ohms B. 8 ohms C. 4 ohms D. 3 ohms

C. Ideal voltmeters have infinite resistance, and ideal ammeters have no resistance.

6.15 Which of the following best characterizes ideal voltmeters and ammeters? A. Ideal voltmeters and ammeters have infinite resistance. B. Ideal voltmeters and ammeters have no resistance. C. Ideal voltmeters have infinite resistance, and ideal ammeters have no resistance. D. Ideal voltmeters have no resistance, and ideal ammeters have infinite resistance.

A. 0 V

6.2 A charge of 2 microC flows from the positive terminal of a 6 V battery, through a 100 ohm resistor, and back through the battery to the positive terminal. What is the total potential difference experienced by the charge? A. 0 V B. 0.002V C. 0.2 V D. 6 V

B. 1:2

6.3 The resistance of two conductors of equal cross-sectional area and equal lengths are compared, and are found to be in the ratio 1:2. The resistivities of the materials from which they are constructed must therefore be in what ratio? A. 1:1 B. 1:2 C. 2:1 D. 4:1

D. 1.55 V

6.4 A voltaic cell provides a current of 0.5 A when in a circuit with a 3 ohm resistor. If the internal resistance of the cell is 0.1 ohms, what is the voltage across the terminals of the battery when there is no current flowing? A. 0.05 V B. 1.5 V C. 1.505 V D. 1.55 V

A. 1:3

6.5 A transformer is a device that takes an input voltage and produces an output voltage that can be either larger or smaller than the input voltage, depending on the transformer design. Although the voltage is changed by the transformer, energy is not, so the input power equals the output power. A particular transformer produces an output voltage that is 300 percent of the input voltage. What is the ratio of the output current to the input current? A. 1:3 B. 3:1 C. 1:300 D. 300:1

B. 6.67 ohms

6.6 Given that R1 = 20 ohms, R2 = 4 ohms, R3 = R4 = 32 ohms, R5 = 15 ohms, and R6 = 5 ohms, what is the total resistance in the setup shown below? A. 0.15 ohms B. 6.67 ohms C. 16.7 ohms D. 60 ohms

A. 5.18 x 10^-3 moles

6.7 How many moles of electrons pass through a circuit containing a 100 V battery and a 2 ohm resistor over a period of 10 seconds? (Note: F = 9.65 x 10^4 C/mol e-). A. 5.18 x 10^-3 moles B. 500 moles C. 5.18 x 10^3 moles D. 5.2 x 10^6 moles

C. 5 V

6.8 In the circuit below, what is the voltage drop across the 2/3 resistor? A. 1/2 V B. 2/3 V C. 5 V D. 7.5 V

D. Cf = 4 Ci

6.9 If the area of a capacitor's plates is doubled while the distance between them is halved, how will the final capacitance (Cf) compare to the original capacitance (Ci)? A. Cf = Ci B. Cf = 1/2 Ci C. Cf = 2 Ci D. Cf = 4 Ci

C. not shatter because the applied frequency is not equal to the natural frequency of the glass.

7.1 An opera singer has two precisely identical glasses. The singer produces as pure a tone as possible and shatters the first glass at a frequency of 808 Hz. She then sings a frequency of 838 Hz in the presence of the second glass. The second glass will likely: A. shatter after a longer amount of time because the applied frequency is higher. B. shatter after a shorter amount of time because the applied frequency is higher. C. not shatter because the applied frequency is not equal to the natural frequency of the glass. D. not shatter because higher frequency sounds are associated with more attenuation.

A. 2 cm

7.10 If two waves with the same frequency are 180 degrees out of phase, what is the amplitude of the resultant wave if the amplitudes of the original waves are 5 cm and 3 cm? A. 2 cm B. 3 cm C. 5 cm D. 8 cm

B. The pitch of the sound will go down.

7.2 A child is practicing the first overtone on his flute. If his brother covers one end of the flute for a brief second, how will the sound change, assuming that the new pitch represents the first overtone in the new setup? A. The pitch of the sound will go up. B. The pitch of the sound will go down. C. The pitch of the sound will not change. D. The change in the pitch depends on the starting pitch.

C. The magnitude of the angular frequency is larger than the magnitude of the frequency.

7.3 Which of the following is necessarily true regarding frequency, angular frequency, and period of a given wave? A. The magnitude of the angular frequency is larger than the magnitude of the period. B. The product of the frequency and period is equal to the angular frequency. C. The magnitude of the angular frequency is larger than the magnitude of the frequency. D. The product of the angular frequency and period is 1.

B. travel time of the reflected sound.

7.4 Ultrasound machines calculate distance based upon: A. intensity of the reflected sound. B. travel time of the reflected sound. C. angle of incidence of the sound. D. the detected frequency of the sound.

A. III only

7.5 The period of a certain wave is 34 ms. If there is a Doppler shift that doubles the perceived frequency, which of the following must be true? I. The detector is moving toward the source at a velocity equal to the speed of sound. II. The source is moving toward the detector at a velocity equal to half the speed of sound. III. The perceived period is 17 ms. IV. The perceived period is 68 ms. A. III only B. I and IV only C. II and III only D. I, II, and IV only

B. 0.03 s

7.6 If the speed of a wave is 3 m/s and its wavelength is 10 cm, what is its period? A. 0.01 s B. 0.03 s C. 0.1 s D. 0.3 s

D. 340pi radians per second

7.7 What is the angular frequency of the third harmonic in a pipe of length 1.5 m with one closed end? (Note: The speed of the sound is approximately 340 m/s.) A. 170 radians per second B. 170pi radians per second C. 340 radians per second D. 340pi radians per second

C. 100

7.8 A certain sound level is increased by 20 dB. By what factor does its intensity increase? A. 2 B. 20 C. 100 D. log 2

B. A decrease in the perceived volume of sounds

7.9 In some forms of otosclerosis, the stapedial foot plate, which transmits vibrations from the bones of the middle ear to the fluid within the cochlea, can become fixed in position. This limits the displacement of the stapedial foot plate during vibration. Based on this mechanism, which of the following symptoms would most likley be seen in an individual with otosclerosis? A. An increase in the perceived volume of sounds B. A decrease in the perceived volume of sounds C. An increase in the perceived pitch of sounds D. A decrease in the perceived pitch of sounds