Newton’s Laws ThermoE&MPotpourri IPotpourri II

A 2 ‑ kilogram block slides down a 30° incline as shown above with an acceleration of 2 meters per second squared.

When a person stands on a rotating merry ‑ go ‑ round, the frictional force exerted on the person by the merry ‑ go ‑ round is (A) greater in magnitude than the frictional force exerted on the person by the merry ‑ go ‑ round (B) opposite in direction to the frictional force exerted on the merry ‑ go ‑ round by the person (C) directed away from the center of the merry ‑ go ‑ round (D) zero if the rate of rotation is constant (E) independent of the person's mass

(B) opposite in direction to the frictional force exerted on the merry ‑ go ‑ round by the person

A ball attached to a string is whirled around in a horizontal circle having a radius r. If the radius of the circle is changed to 4r and the same centripetal force is applied by the string, the new speed of the ball is which of the following? (A) One ‑ quarter the original speed (B) One ‑ half the original speed (C) The same as the original speed (D) Twice the original speed (E) Four times the original speed

(D) Twice the original speed

From the top of a high cliff, a ball is thrown horizontally with initial speed v o. Which of the following graphs best represents the ball's kinetic energy K as a function of time t ?

A railroad flatcar of mass 2,000 kilograms rolls to the right at 10 meters per second and collides with a flatcar of mass 3,000 kilograms that is rolling to the left at 5 meters per second. The flatcars couple together. Their speed after the collision is (A) 1 m/s (B) 2.5 m/ s (C) 5 m/ s (D) 7 m/ s (E) 7.5 m/ s

(A) 1 m/s

An ideal gas is made up of N diatomic molecules, each of mass M. All of the following statements about this gas are true EXCEPT: (A) The temperature of the gas is proportional to the average translational kinetic energy of the molecules. (B) All of the molecules have the same speed. (C) The molecules make elastic collisions with the walls of the container. (D) The molecules make elastic collisions with each other. (E) The average number of collisions per unit time that the molecules make with the walls of the container depends on the temperature of the gas.

(B) All of the molecules have the same speed.

An ideal gas confined in a box initially has pressure p. If the absolute temperature of the gas is doubled and the volume of the box is quadrupled, the pressure is (A) p/8 (B) p/4 (C) p/2 (D) p (E) 2p

(C) p/2

For the process Y  Z, Q is greater than zero and (A)W<0 and  U=0 (B) W=0 and  U<0 (C) W=0 and  U>0 (D) W >0 and  U=0 (E) W>0 and  U>0

(C) W=0 and  U>0

Which of the following is always a characteristic of an adiabatic process? (A) The temperature does not change (  T = 0). (B) The pressure does not change (  P = 0). (C) The internal energy does not change (  U = 0). (D) No heat flows into or out of the system (Q = 0) (E) No work is done on or by the system (W = 0)

(D) No heat flows into or out of the system (Q = 0)

Heat is added at a constant rate to a sample of pure substance that is initially a solid at temperature To. The temperature of the sample as a function of time is shown in the graph above. From the graph, one can conclude that the (A) substance sublimes directly from the solid phase to the vapor phase (B) melting point is T2 (C) specific heat is greater for the liquid phase than for the solid phase (D) heat of fusion and heat of vaporization are equal (E) specific heat of the solid increases linearly with temperature

(C) specific heat is greater for the liquid phase than for the solid phase

Which two arrangements of resistors shown above have the same resistance between the terminals? (A) I and II (B) I and IV (C) II and III (D) II and IV (E) III and IV

(B) I and IV

A hollow metal sphere of radius R is positively charged. Of the following distances from the center of the sphere, which location will have the greatest electric field strength? (A) 0 (center of the sphere) (B) 3R/2 (C) 5R/4 (D) 2R (E) None of the above because the field is of constant strength

(C) 5R/4

Two capacitors are connected in parallel as shown above. A voltage V is applied to the pair. What is the ratio of charge stored on C1 to the charge stored on C2, when C1 = 1.5C2 ? (A) 4/9 (B) 2/3 (C) 1 (D) 3/2 (E) 9/4

(D) 3/2

The figure above shows a rectangular loop of wire of width l and resistance R. The loop is pulled to the right at a constant speed v. What are the magnitude and direction of the induced current in the loop? MagnitudeDirection (A) BlvR Clockwise (B) BlvR Counterclockwise (C) Blv/RClockwise (D) Blv/RCounterclockwise (E)0Undefined

MagnitudeDirection (C) Blv/RClockwise

Which of the paths above represents the path of an electron traveling without any loss of energy through a uniform magnetic field directed into the page? (A) A (B) B (C) C (D) D (E) E

(D) D

For the photoelectric effect, which graph best shows the maximum kinetic energy K of the photoelectrons as a function of the frequency of incident light? (A) A(B) B(C) C(D) D(E) E

(A)

A simple pendulum of length l. whose bob has mass m, oscillates with a period T. If the bob is replaced by one of mass 4m, the period of oscillation is (A) T (B) T (C) T (D) 2T (E)4T

(C) T

A hollow metal sphere of radius R is positively charged. Of the following distances from the center of the sphere, which location will have the greatest electric field strength? (A)0 (center of the sphere) (B) 3R/2 (C) 5R/4 (D) 2R (E) None of the above because the field is of constant strength

(C) 5R/4

The mass of Planet X is one ‑ tenth that of the Earth, and its diameter is one ‑ half that of the Earth. The acceleration due to gravity at the surface of Planet X is most nearly (A) 2m/s2 (B) 4m/s2 (C) 5m/s2 (D) 7 m/s2 (E) 10 m/s2

(B) 4m/s2

Light leaves a source at X and travels to Y along the path shown above. Which of the following statements is correct? (A) The index of refraction is the same for the two media. (B) Light travels faster in medium 2 than in medium 1. (C) Snell's law breaks down at the interface. (D) Light would arrive at Y in less time by taking a straight line path from X to Y than it does taking the path shown above. (E) Light leaving a source at Y and traveling to X would follow the same path shown above, but in reverse.

An object is placed as shown in the figure above. The center of curvature C and the focal point F of the reflecting surface are marked. As compared with the object, the image formed by the reflecting surface is (A) erect and larger (B) erect and the same size (C) erect and smaller (D) inverted and larger (E) inverted and smaller

Which color of light emitted from an atom would be associated with the greatest change in energy of the atom? (A) Blue (B) Green (C) Red (D) Violet (E) Yellow

(D) Violet

The deuteron mass m d is related to the neutron mass m n and the proton mass m p by which of the following expressions? (A)m d = m n ‑ m p (B) m d = m n + m p (C) m d =2(m n +m p ) (D) m d = m n + m p ‑ (mass equivalent to deuteron binding energy) (E) m d = m n + m p + (mass equivalent to deuteron binding energy)

(D) m d = m n + m p ‑ (mass equivalent to deuteron binding energy)

Which of the following is true of a single ‑ slit diffraction pattern? (A) It has equally spaced fringes of equal intensity. (B) It has a relatively strong central maximum. (C) It can be produced only if the slit width is less than one wavelength. (D) It can be produced only if the slit width is exactly one wavelength. (E) It can be produced only if the slit width is an integral number of wavelengths

(B) It has a relatively strong central maximum.

Which of the following statements Is true of a beta particle? (A) Its speed in a vacuum is 3 x 10^8 m/s. (B) It has a charge equal and opposite to that of an alpha particle. (C) It is more penetrating than a gamma ray of the same energy. (D) It has a mass of about 1,840 times that of a proton. (E) It can exhibit wave properties.

(E) It can exhibit wave properties.

Light leaves a source at X and travels to Y along the path shown above. Which of the following statements is correct? (A)The index of refraction is the same for the two media. (B) Light travels faster in medium 2 than in medium 1. (C) Snell's law breaks down at the interface. (D) Light would arrive at Y in less time by taking a straight line path from X to Y than it does taking the path shown above. (E) Light leaving a source at Y and traveling to X would follow the same path shown above, but in reverse.