1. Which of the following represents the vector sum of vector Q and vector R? 4 страница

(A) 34 m/s toward the observer

(B) 34 m/s away from the observer

(D) 68 m/s away from the observer

(E) 90 m/s away from the observer

27. If q₁ and q₂ are both positively charged, and q₂ is released, what is the maximum velocity that can be achieved by q₁?

E is the electric field created by q₁. V is the voltage at a given point in the field E. Assume that the electric field created by q₂ is negligible compared to E. k is Coulomb’s Law constant. m₁ is the mass of q ₁, and m₂ is the mass of q₂

(A)

(B)

(C)

(D)

(E)

28. What is the voltage across the 3 ohm resistor and the current through the 3 ohm resistor in the circuit shown below?

(A) 10 V, 3 A

(B) 12 V, 6 A

(D) 18 V, 10 A

(E) None of these.

29. If the distance between the plates on the capacitor were doubled, the energy stored in the capacitor would:

(A) decrease by a factor of 2.

(B) remain the same.

(D) increase by a factor of 4.

(E) decrease by a factor of 4.

30. A piece of iron is wrapped by copper wire as shown. Which of the following is correct?

(A) A current in the wire will turn the iron into a magnet.

(B) If the iron is magnetized, a current will be produced in the wire.

(D) Neither A or B is true.

(E) None of these.

TEST 07

1. Which of the following is true if the product of vectors Q and R is a vector?

(A) The vector product will point in the direction of Q and have a magnitude proportional to the cosine of the angle between Q and R

(B) The vector product will point in the direction of Q and have a magnitude proportional to the sine of the angle between Q and R.

(C) The vector product will point in a direction perpendicular to both Q and R, and have a magnitude proportional to the cosine of the angle between Q and R.

(D) The vector product will point in a direction perpendicular to both Q and R, and have a magnitude proportional to the sine of the angle between Q and R

(E) The vector product will point in a direction horizontal to both Q and R, and have a magnitude proportional to the sine of the angle between Q and R

2. A particle starts from rest and accelerates for 4 seconds at 10 m/s². What is its displacement from its initial position?

(A) 16 m

(B) 40 m

(D) 120 m

(E) 150 m

3. If the graphs shown are displacement versus time graphs, the area under the curve represents:

(A) displacement

(B) velocity

(D) none of these

(E) all of these

4. How are time t and angle related?

(A) As increases t increases.

(B) As increases t decreases.

(D) As increases t remains the same.

(E) As decrease t increases.

5. When air resistance is considered, a spherical projectile will go farther if:

(A) the projectile has greater mass.

(B) the initial velocity of the projectile is decreased.

(D) the density of air is increased.

(E) None of these

6. A 9 kg block experiences a net force in the opposite direction of its velocity for 3 seconds. Its velocity decreases by 9 m/s. What is the magnitude of the force?

(A) 1 N

(B) 9 N

(D) 27 N

(E) 40 N

7. If h is 5 m, m is 2 kg, d is 25 m, and the mass starts from rest, how long does it take the mass to move the distance d?

The question refers to the frictionless inclined plane shown below, h is the height of the ramp, d is the total length of the ramp, and 0 is the angle the ramp is placed from the horizontal. (Note: the distance x is also frictionless.)

(A) 2 s

(B) 5 s

(D) 20 s

(E) 30 s

8. Which of the following properties affects the coefficient of static friction between a block and an inclined plane?

(A) gravity

(B) the mass of the block

(D) the material of the block and plane

(E) none of these

9. A 10 kg mass hangs from a spring that follows Hooke’s Law. If the spring has a spring constant of 200 N/m, how far does the spring distend from its rest position?

(A) 0.05 m

(B) 0.5 m

(D) 2000 m

(E) 2500 m

10. The plane below is inclined at a 60° angle. The coefficient of static friction between the mass and the plane is 0.2. The mass is 100 kg. What is the minimum force F necessary to start the object moving up the plane?

(A) 500 N

(B) 766 N

(D) 966 N

(E) 999 N

11. What is the net force on the dipole inside the capacitor?

(A) 0 N

(B) 5 N

(D) 200 N

(E) 220 N

12. Force F is 20 N, m is 100 kg, and is 60°. If both forces are applied for 1 second, how much work is done on the block?

(A) 0 J

(B) 8.7 J

(D) 30 J

(E) 40 J

13. In 0.5 s, a hammer drives a 30 cm nail into a piece of wood. If the frictional force between the nail and the wood is 200 N, approximately how much work is done by the hammer?

(A) 30 J

(B) 60 J

(D) 600 J

(E) 900 J

14. Which of the following is not true concerning elastic collisions?

(A) Only conservative forces are involved in elastic collisions.

(B) The sum of the kinetic energies of the colliding objects is always conserved.

(D) The sum of the momentums of the colliding objects is always conserved.

(E) none of these

15. What is the average force on the mass in the first 20 seconds?

(A) 2.5 N

(B) 5 N

(D) 100 N

(E) 250 N

16. If the same force F is applied through 10 cm by each lever, which lever lifts the mass to the greatest height?

Each lever stick is one meter long and massless. The triangle beneath each lever represents the fulcrum. The circle represents the point 25 cm from the right end of the lever stick.

(A) X only

(B) Y only

(D) All do the same amount of work.

(E) None of these

17. Which of the following is true concerning positron emission?

(A) A proton and a positron are created while a neutron is destroyed.

(B) A proton and a neutron are created while a positron is destroyed.

(D) A proton and a positron are destroyed while a neutron is created.

(E) None of these.

18. Two rooms are connected by a closed door. A scientist finds the mass, density, energy, and pressure of the gas in each room to be identical. The door is opened. The scientist measures the mass, density, energy, and pressure in the two rooms combined. Which values changed in the second measurement?

I. mass

II. density

III. energy

IV. pressure

(A) I and III only

(B) II and IV only

(D) I, II, III, and IV

(E) I and II only

19. Where is the fluid pressure the greatest?

Four fluids with different densities are held in an open container. Each fluid has a depth of 10 m. P₁, P₂, and P₃ are points in the container.

(A) P₁

(B) P₂

(D) The pressure is the same everywhere in the container.

(E) None of these

20. Measuring from the floor, which of the following gives the height of the fluid in each vertical column from highest to lowest?

An ideal fluid with a specific gravity of 1.0 flows through the pipe in the direction from c to a. The pipe has the same diameter at a and c. The vertical pipes are vacuum sealed at the top. The height of the fluid at h₁, h₂, and h₃ are measured from the center of the pipe, and are not drawn to scale.

(A) a > b > c

(B) c > b > c

(D) b > a = c

(E) b = a = c

21. If the blood behaved ideally, where would the pressure be the greatest?

The chart shows the summation of the cross-sectional areas of the different blood vessels of the body starting near the heart, working through the systemic circulatory system and back to the heart.

(A) Aorta

(B) Capillaries

(D) Venae cavae

(E) None of these

22. If the frequency of a wave is 200 Hz, and the wavelength is 2 m, how much time is required for a single wave to pass by an observer?

(A) 0.005 s

(B) 0.050 s

(D) 400 s

(E) 500 s

23. What are the equivalent SI units for dB?

(A) W/m²

(B) W/s

(D) Decibels represent a ratio and thus have no equivalent units in the SI sytem.

(E) None of these.

24. How does the period of the first harmonic for the note played by the flute compare with the period of the wave form shown?

When an instrument plays a note, the resulting sound is a combination of all the possible harmonics for that instrument in its momentary configuration. For instance, a musician changes notes on a violin by pressing the strings against the neck of the instrument, thus shortening the string length and changing the possible harmonics. A given shortened string will play at one time all the possible harmonics allowable by its string length. A given note is the same set of harmonics for all instruments. The diagram below shows the sound waves of the same note played by three different instruments.

(A) The period for the first harmonic is half as great.

(B) The period for the first harmonic is the same.

(D) The period for the first harmonic is four times as great.

(E) None of these.

25. If the other end of the string were tied to a wall and the string were resonating at its third harmonic, which of the following would represent the length of the string? (Hint: Assume that a node exists at both ends of the string.)

A mass m is suspended by a spring with a spring constant k. The rest length of the spring is x₀, and it oscillates a distance above and below its rest position. A very long string with a mass per unit length . and constant tension T is attached to the mass as shown. The moving mass creates a wave on the string with a wavelength , a frequency f, an amplitude A, and a velocity v.

(A)

(B)

(C)

(D)

(E)

26. An observer moves at 1/10 the speed of sound toward a stationary sound source. If the source emits sound waves with a wavelength , what is the approximate wavelength perceived by the observer?

(A)

(B)

(C)

(D)

(E)

27. The Na⁺/K⁺ pump pumps three positively charged ions out of a neuron, while pumping 2 equally positively charged ions into the neuron. If this action establishes the an electric potential across the membrane, the direction of the electric field is:

(A) from the inside toward the outside.

(B) from the outside toward the inside.

(D) along the axon away from the axon terminals.

(E) None of these.

28. What is the voltage across the 2 ohm resistors and the current through either 2 ohm resistors?

(A) 3 V, 3/2 A

(B) 3 V, 3 A

(D) 6 V, 8 A

(E) 8 V, 8 A

29. What is the effective capacitance of the three capacitor unit below?

(A) 1/3

(B) 1

(D) 9

(E) 10

30. Which of the following most likely represents the current i generated within the coil as a function of time?

A conducting coil is rotated at a constant speed in an external magnetic field as shown. A current is generated wit hin the loop. T represents the time required for the loop to make one full rotation.

(A)

(B)

(C)

(D)

(E) None of these.

TEST 08

2. A particle starts from rest and accelerates at 10 m/s². How long does it take for the particle to travel 45 m?

(A) 2 s

(B) 3 s

(D) 45 s

(E) 60 s

3. If the graphs shown are displacement versus time graphs, which graph represents a particle with positive acceleration?

(A) W only

(B) X only

(D) W and X only

(E) W, Y and X only

4. Ignoring air resistance, which of the following properties of a projectile remains constant throughout its flight?

(A) vertical velocity

(B) horizontal velocity

(D) displacement

(E) none of these

5. A lead ball is dropped from a height of 20 m. When air resistance is considered, approximately how long does it take for the ball to strike the ground?

(A) 1.4 s

(B) 2 s

(D) 4 s

(E) 5 s

6. A 5 kg block accelerates at 10 m/s². What is the magnitude of the net force?

(A) 0.2 N

(B) 0.5 N

(D) 50 N

(E) 80 N

7. If h is 5 m and the mass takes 3 s to move the distance d when starting from rest, what is the distance d?

(A) 2 s

(B) 5 s

(D) 20 s

(E) 30 s

8. A block is at rest on a plane inclined at an angle of 0. Which of the following is a true statement?

(A) The static frictional force on the block is greater than the force due to gravity down the inclined plane.

(B) The net force on the block is in the upward direction along the inclined plane.

(D) There is no net force on the block.

(E) None of these

9. A 2 kg mass is pushed against a spring (k = 400 N/m), compressing the spring 5 cm from its rest position. The mass sits on a frictionless surface. Which of the following accurately describes what will happen after the mass is released, but before the spring reaches its relaxed position?

(A) The velocity and the acceleration of the mass will continually decrease.

(B) The velocity and the acceleration of the mass will continually increase.

(D) The velocity of the mass will continually decrease, but the acceleration will continually increase.

(E) None of these

10. Which of the following must be true of magnitudes of the tensions given in the diagram?

(A) T₁ > T₂

(B) T₂> T₁

(D) T₁ + T₂ = T₃

(E) T₁ - T₂ = T₃

11. A 75 kg man holds a 25 kg pole at a 60° angle as shown. He leans backward at a 60° angle so that his center of gravity is 0.5 m to the right of his feet. How long is the pole?

(A) 4 m

(B) 6 m

(D) 8 m

(E) 9 m

12. Force F is 200 N, m is 100 kg, and is 60°. If the block moves 10 m to the left, how much work is done on the block?

(A) 900 J

(B) 1000 J

(D) 2100 J

(E) 2300 J

13. In 0.5 s, a hammer drives a 30 cm nail into a piece of wood. If the frictional force between the nail and the wood is 200 N, how much power is dissipated by the friction?

(A) 30 J

(B) 60 J

(D) 600 J

(E) 900 J

14.A 2 kg ball moving at 4 m/s collides elastically with a 6 kg ball that is stationary. If the 2 kg ball bounces off with a speed of 2 m/s, what is the speed of the 6 kg ball?

(A) ¹/₃ m/s

(B) ²/₃ m/s

(D) 3 m/s

(E) 4 m/s

15. How fast is the particle moving at t = 20 s?

(A) 0 m/s

(B) 50 m/s

(D) 250 m/s

(E) 500 m/s

16. If same force F is applied through 10 cm by each lever, which lever gives the mass the greatest final velocity?

Each lever stick is one meter long and massless. The triangle beneath each lever represents the fulcrum. The circle represents the point 25 cm from the right end of the lever stick.

(A) X only

(B) Y only

(D) All do the same amount of work.

(E) None of these

17. Which of the following is true concerning electron capture?

(A) A proton and an electron are created while a neutron is destroyed.

(B) A proton and a neutron are created while an electron is destroyed.

(D) A proton and an electron are destroyed while a neutron is created.

(E) None of these.

18. Which of the following phases typically exhibits large changes in density?

I. solid

II. liquid

III. gas

(A) I only

(B) II only

(D) I, II, and III

(E) I and II only

19. If the values of ₁, ₂, ₃, and ₄ are 500 kg/m³, 1000 kg/m³, 2000 kg/m³, and 4000 kg/m³, respectively, then what is the approximate pressure at P₃?

Four fluids with different densities are held in an open container. Each fluid has a depth of 10 m. P₁, P₂, and P₃ are points in the container.

(A) 0.5 atm

(B) 1.5 atm

(D) 8.5 atm

(E) 10.5 atm

20. Which of the following represents the relative velocities at a, b, and c?

(A) a > b > c

(B) c > b > a

(D) a = c > b

(E) b = a = c

21. Which of the following is the best explanation for why the stream of water in a faucet attenuates as it falls?

(A) Atmospheric pressure squeezes the stream of water.

(B) The pressure in the stream decreases as its velocity increases allowing the cohesive forces between the molecules to attenuate the stream.

(C) The pressure in the stream increases as its velocity increases allowing the cohesive forces between the molecules to attenuate the stream.

(D) The density of the stream decreases as the velocity increases which results in a decrease in volume.

(E) None of these.

22. If the frequency of a wave is 200 Hz, and the wavelength is 2 m, what is the velocity of the wave?

(A) 0.05 m/s

(B) 0.50 m/s

(D) 400 m/s

(E) 500 m/s

23. What purpose is served by measuring intensity level in terms of decibels and not W/m²?

(A) Decibels measure absolute power as opposed to power per unit area.

(B) The decibel system is more accurate.

(D) Decibels are used to honor Alexander Graham Bell.

(E) None of these.

24. How does the period of the second harmonic for the note played by the oboe compare with the period of the wave form shown?

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