Part 1 – Questions from weeks 12 - 14

 

1/ Place a bright light bulb far in front of a converging lens. The image is…

(A) …real and upright.

(B) …real and inverted.

(C) …virtual and magnified.

(D) …virtual and reduced.

(E) …fuzzy because the light is not at the focal point.

 

2/ If the light bulb in Question 1 is 20 cm from the lens, and the focal length of the lens is 3.3 cm, the position of the image is

(A) 4.0 cm on the other side of the lens

(B) 4.0 cm on the same side of the lens

(C) 3.3 cm on the other side of the lens

(D) 3.3 cm on the same side of the lens

 

 

 

4/ Nanotechnology may become an important technology of the future. Estimate the number of atoms in a device with dimensions 14 nm × 14 nm × 8 nm. (nm = nanometer = 10-9 m)

(A) 1,600     (B) 40,000     (C) 100 million     (D)  200,000

 

 

5/ Methane (CH4) is the smallest hydrocarbon molecule, and the major constituent of natural gas—an important energy source. Which choice describes the molecule?

(A) 5 atomic nuclei and 10 electrons

(B) 5 atomic nuclei and 5 electrons

(C) 1 atomic nucleus and 10 electrons

(D) 1 atomic nucleus and 5 electrons

(E) 5 atoms and a variable number of electrons

 

6/ The molecular formula for chlorophyll is C55 H72 Mg N4 O5 . (Just like the molecular formula for water is H20 .)

Estimate the molecular mass of chlorophyll. Base your estimate on the most common isotopes of C, H and O; the atomic mass of magnesium (Mg) is 24 and that of nitrogen (N) is 14.

(A) 512     (B) 137     (C) 892     (D) 1024

 

7/ The atomic number of uranium is 92. The most common isotope of uranium is U-238, with mass number 238. Which choice describes the subatomic particles in an atom of U-238?

(A) 92 electrons, 92 protons and 238 neutrons

(B) 92 electrons, 92 protons and 146 neutrons

(C) 146 electrons, 92 protons and 92 neutrons

(D) 146 electrons, 146 protons and 92 neutrons

(E) 92 electrons, 92 protons, and a variable number of neutrons

 

8/ The half-life of carbon-14 (C14) is 5730 years. An archeologist finds plant remains at an ancient site; she measures that the C14 content is 0.13 times the C14 content of a modern plant sample. Calculate the age of the archeological site.

(A) 16,900 yr     (B) 13,400 yr     (C) 23,800 yr     (D) 20,200 yr

 

9/ The deuterium-tritium (DT) nuclear reaction is

D + T → helium-4 + neutron .

The four masses are:

Mass of D = 2.014102 u ;     Mass of T = 3.016049 u ;

Mass of He-4  = 4.002603 u ;     Mass of n = 1.008665 u

where 1 u = 931.5 MeV/c2. How much energy is released in one DT reaction?

(A) 1.8 MeV     (B) 6.8 MeV     (C) 17.6 MeV     (D) 21.4 MeV

 

10/ The U. S. Department of Energy has provided funds for nuclear fusion research. Nuclear fusion reactors may become feasible in the future. Which reaction is most likely to be used in the first practical fusion reactors? (g = photon, n = neutron, p = proton)

(A) 1H + n → 2H + g          (B) 1H + 2H → 3He + g

(C) 2H + 2H → 3He + n          (D) 2H + 3H → 4He + n

(E) 2H + 4He → 5He + p

 

Part 2 – Questions from the whole semester

 

11/ A race car accelerates on a straight track from speed 0 to speed 10 m/s in 3 seconds. The mass of the car is 700 kg and the mass of the driver is 50 kg. Calculate the net force on the car.

(A) 2.50 × 104 N       (B) 2.33 × 104 N

(C) 2.50 × 103 N       (D) 2.33 × 103 N

 

 

12/ The curved track in the figure to the right is an arc of a circle with radius R = 3 m. The block slides without friction down the track, in Earth’s gravity, starting from rest at height H = 3 m. Calculate the speed of the block at the bottom (point F).

(A) 6.6 m/s         (B) 7.7 m/s     (C) 5.5 m/s         (D) 8.8 m/s

 

 

 

 

13/ The steel ball (speed = 5 m/s before the collision) hits the wood ball (speed = 0 before the collision) head on. The balls have the same size (but different mass). Compare the forces on the balls during the collision.

(A) The steel ball exerts a greater force because it has greater mass.

(B) The steel ball exerts a greater force because it is moving.

(C) The forces exerted by the two balls are equal.

(D) The wood ball exerts a greater force because it is not moving.

(E) The wood ball exerts a greater force because it has greater mass.

 

14/ Suppose a comet in the Solar System revolves around the sun on an orbit with aphelion distance = 70 AU and perihelion distance = 2 AU. Then what is the period of revolution?

(A) 108 yr     (B) 216 yr     (C) 324 yr     (D) 72 yr

 

 

15/ As the magnet moves toward the coil of wire, a current will flow around the coil of wire. Why?

(A) An electric field is induced with directions tangent to the coil of wire.

(B) A current is induced by any flux.

(C) Current creates magnetism (Ampere’s law).

(D) Current will not flow because there is no battery.

(E) Electrons are forced by the magnetic field (Lorentz force).

 

16/ Two long parallel wires carry equal currents, I = 5 A, in opposite directions. The distance between the wires is d = 1 cm. Calculate the magnetic field at point P (half way between the wires).

(A) 4.0 × 10-4 T          (B) 6.0 × 10-4 T

(C) 4.0 × 10-3 T          (D) 6.0 × 10-3 T

 

17/ Which statement best describes properties of an electric field?

(A) It has a quantity of energy.

(B) It can exert a force on a particle.

(C) It can exist where no electric charge is present.

(D) All of the above.

(E) None of the above.

 

18/ Is an energy crisis possible?

(A) Yes, because energy gets used up.

(B) No, because energy is constant.

(C) Yes, because a shortage of an important energy source might occur.

(D) No, because new energy sources can be developed when needed.

(E) No, because the law of conservation of energy prevents an energy crisis.

 

19/ Petroleum and natural gas are very rare in the geology of Michigan (MI). Which answer explains this statement?

(A) Dinosaur fossils do not occur in MI.

(B) Hot geological processes do not occur in MI.

(C) MI is continental not marine.

(D) The statement is false – oil and gas are not rare in MI.

(E) Oil and natural gas deposits are random.

 

20/ What is light?

(A) An effect of vision

(B) A stream of positive and negative particles

(C) Pure energy

(D) A wave of magnetic field

(E) None of the above

 

21/ The sky is blue. The reason is because white sunlight scatters from atmospheric molecules …

(A) …and changes to blue.

(B) …more intensely for high frequencies.

(C) …more intensely for low frequencies.

(D) …and the red light is absorbed.

(E) …and red wavelengths get shifted to blue.

 

23/ Advanced technologies have developed because…

(A) humans are so clever.

(B) people obtained knowledge from space aliens.

(C) humans needed technology for survival.

(D) capitalism made technology possible by rewarding inventors.

(E) nature is simple enough for human understanding.

 

24/ The purpose of science is …

(A) to understand the mystery of the physical world.

(B) to develop better technology.

(C) to reveal universal principles of nature.

(D) all of the above.

(E) none of the above — science is just a temporary human construct.

 

25/ The Scientific Revolution that began in the 16th century in Europe was based most strongly on …

(A) experimentation and mathematical analysis.

(B) common sense.

(C) the opinions of a few isolated geniuses.

(D) philosophical ideas from ancient theories.

(E) purely experimentation.

 

26/ The Earth rotates by one full rotation every 24 hours. What force (or torque) causes the rotation?

(A) No force or torque

(B) Gravity

(C) Momentum

(D) Inertia force

(E) Angular motion

 

27/ The weather today (December) is quite different from our first class (August). Why? (Select the best choice.)

(A) The Earth is now farther from the sun.

(B) The Earth is now closer to the sun.

(C) The northern hemisphere now tilts away from the sun.

(D) The axis of rotation has changed.

(E) The sun has moved south of the equator.