Exam 1

Part A. (25 questions, 50 points total)

1. The physical sciences include astronomy, physics, chemistry, biochemistry, genetics, and earth sciences.

a) true; b) false

2. An atom of the carbon-14 isotope contains which and how many particles in its nucleus?

a) 6 protons
b) 14 protons, 8 neutrons, and 14 electrons
c) 6 protons and 8 neutrons
d) 6 protons, 8 neutrons, and 6 electrons
e) none of the above

3. Assuming that the radius of Jupiter is 9 times greater than the radius of Earth, what would be the ratio between Jupiter's surface area and Earth's surface area?

a) 9 to 1
b) 18 to 1
c) 81 to 1
d) 729 to 1
e) none of the above

4. The Jovian planets are: Mercury, Venus, Earth, and Mars.

a) true; b) false

5. The existence of seasons is due to the

a) Earth's revolution around the sun
b) Earth's rotation around its axis
c) the tilt of Earth's axis with respect to its orbit around the sun
d) both a) and b)
e) none of the above

6. Precision refers to how close a measurement of a quantity comes to the accepted or true value of that quantity.

a) true; b) false

7. The four phases of matter are:
a) weak, strong, electromagnetic and gravitational
b) length, mass, time, and energy
c) plasma, gas, liquid, and solid
d) all of the above
e) none of the above

8. Weight and mass represent the same physical quantity.

a) true; b) false

9. The day is based on one
a) revolution of the Earth
b) rotation of the Earth
c) orbit of the moon around the Earth
d) orbit of the North Star around the Earth
e) none of the above

10. An asteroid is an icy, dusty body, a few kilometers, or less, in diameter that typically orbits the sun in a large and elongated elliptical orbit.
An asteroid passing near the sun may become visible and form a tail.

a) true; b) false

11. Astronomers use the light-year to measure the _______ traveled by _______ in one year.

a) time ……….. light
b) distance ……….sound
c) distance ………..light
d) none of the above
e) all of the above
12. How many milligrams are in one centigram of water?

a) 1
b) 10
c) 100
d) 0.1
e) 0.01

13. The strong force (the strongest among the four fundamental forces) acts outside the atomic nuclei.

a) true; b) false

14. Atoms of an element

a) cannot be disassembled by any means
b) overall, are not electrically charged
c) never link up with each other
d) none of the above
e) all of the above

15. The four fundamental properties are: length, time, mass, and charge.

a) true; b) false

16. How many neutrons exist in an atom of the isotope given by the symbol ?
a) 6
b) 14
c) 8
d) 20
e) 4

17. The ecliptic plane is the plane defined by Earth's revolution around the sun.

a) true; b) false

18. In 5.5 kilometers there are centimeters

a) 550
b) 5,500
c) 550,000
19. Which of the following chemical equations is unbalanced?

a) NH3 + O2 à NO + H2O
b) CH4 + 2O2 à CO2 + 2H2O
c) NH4NO3 à NH4 + NO3
d) none of the above

20. An electron is a positively charged subatomic particle and one of the three basic constituents of an atom.

a) true; b) false

21. One gram of lead and 1 gram of leaves do not differ from each other in
a) volume
b) density
c) the number of atoms they contain
d) mass
e) none of the above

22. An element is a substance consisting solely of atoms having the same number of nucleons

a) true; b) false

23. Entropy measures the order within a system.

a) true; b) false

24. Gravitational force is significant at
a) macroscopic scales
b) microscopic scales
c) both microscopic and macroscopic scales
d) it is not significant at any scales, because it describes the interaction between masses
e) at none of the above scales

25. Astronomical unit refers to the average distance between Earth and Sun, equivalent to about 150 million kilometers.

a) true; b) false
d) 55,000
e) none of the above

Part B. (10 questions, 50 points total)

1. Three cubic meters of a certain type of dry soil have a mass of 6 metric tons (1 metric ton = 1000 Kg). What is the density of this soil. (Show all your work, include units, and start with formula and conversions, if necessary.)

2. What does the term of entropy mean?

3. Which of the four fundamental forces is responsible for the formation of molecules?

4. Assuming that the Earth's circumference is 40,000 Km, how much distance along Earth's surface does 20 of latitude correspond to? How much distance does 10 of longitude correspond to?

5. What is the reason for the existence of the night-and-day cycle?

6. Define/give a short description of the solar eclipse.

7. Which of the four fundamental forces is the strongest, and what it is responsible for?

8. How many millimeters are in one kilometer? Show all your work.

9. Give a short description of the evidence(s) for the validity of the Big Bang Theory.

Exam 2

Part A. (20 questions, 80 points total)

1. Speed and velocity are the same thing; they are identical in every respect.

a) true; b) false

2. In the International System, the standard unit for velocity is expressed in

a) Km/hour
b) miles/hour
c) km/s
d) m/s

3.Which one of the following is a vector quantity ?

a) force
b) density
c) speed
d) time

4. The acceleration represents the ratio between the change in velocity and the time during which the change took place.

a) true; b) false

5. Which one of the following is a scalar quantity?

a) acceleration
b) mass
c) weight
d) velocity

6. Since for momentum both a magnitude and a direction have to be associated and defined, this must be a vector quantity.

a) true; b) false

7. The weight of a body is
a) a measure of its inertia
b) the same quantity as its mass but expressed in different units
c) independent of its mass
d) the force with which it is attracted toward Earth's center

8. Newton's first law of mechanics defines and describes inertia

a) true; b) false

9. To find the linear momentum of a moving body, we must know its

a) volume and acceleration
b) density and volume
c) velocity and mass
d) mass and acceleration

10. Speed is the same in ALL frames of reference

a) true; b) false

11. A body at rest has zero

a) speed
b) kinetic energy
c) both a) and b)
d) none of the above

12. The work done by a force acting on a body of given mass and moving the body through a distance over some period of time is
the product of the average force exerted on the body and the

a) distance moved by the body
b) time during which the force acts on the body
c) mass of the body
d) density of the body

13. The shorter the time during which a given amount of work is done on a body, the greater is the power delivered to the body

a) true; b) false

14. Chemical reaction that release energy are of what type?

a) stratospheric
b) endoergic
c) exothermic
d) mesospheric

15. The Newton is the standard SI unit for force

a) true; b) false

16. The fossil fuels are

a) coal
b) oil
c) natural gas
d) all of the above

17. The Joule is the standard SI unit for energy

a) true; b) false

18. The temperature of a gas is a measure of the

a) average separation of its molecules
b) mass of its molecules
c) average kinetic energy of all its molecules
d) diameter of its molecules

19. The magnitude of the buoyant force exerted on a body in a fluid is always equal to the

a) density of a fluid displaced by the body
b) weight of the fluid displaced by the body
c) volume of the fluid displaced by the body
d) mass of the body

20. The watt is the standard SI unit for power

a) true; b) false

Part B. (4 questions, 20 points total)

1. How long would it take to reach a star (1, 000, 000 km away) if you could fly straight toward it
at the cruising speed of 1, 000 m/s ?

2. What force (magnitude only) is needed to give to a mass of 1.5 kg an acceleration of 10 m/s2 ?

3. A 50-Kg body in motion attains a speed of 10 m/s. What is the kinetic energy at that speed?

4. After you lift a body (with a 2 Kg mass) to a height of 1 m above a desk, how much gravitational potential energy
does the body have relative to the height of the desk? (For simpler calculations, you may use the rounded value of g = 10 m/s2)

10. What is the force that keeps the planets from drifting away from the sun?