Physical Science Study Guide for Final Exam

Unit 1: Patterns of Motion and Equilibrium

• Speed

  • Definition: The distance traveled per unit of time.

  • Formula: ext{Speed} = rac{ ext{Distance}}{ ext{Time}}

• Velocity

  • Definition: Speed with a direction.

  • Example: A car traveling 60 mph north.

• Acceleration

  • Definition: The rate of change of velocity per unit of time.

  • Formula: ext{Acceleration} = rac{ ext{Final Velocity} - ext{Initial Velocity}}{ ext{Time}}

• Net Force

  • Definition: The overall force acting on an object when all the individual forces are combined.

  • Example: If a 10 N force is applied to the right and a 5 N force to the left, the net force is 5 N to the right.

• Dynamic Equilibrium

  • Definition: Occurs when an object is in motion at constant velocity and the sum of the forces acting on it is zero.

• Free Fall

  • Definition: Movement of an object towards Earth solely under the influence of gravity.

  • Acceleration due to gravity: g = 9.81 m/s^2

Unit 2: Newton’s Laws of Motion

• First Law (Inertia)

  • An object at rest stays at rest, and an object in motion stays in motion with the same speed and direction unless acted upon by a net external force.

• Second Law (F=ma)

  • The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

  • Formula: F = m imes a

• Third Law (Action-Reaction)

  • For every action, there is an equal and opposite reaction.

Unit 3: Momentum and Energy

• Kinetic Energy

  • Definition: The energy of an object due to its motion.

  • Formula: KE = rac{1}{2}mv^2

• Potential Energy

  • Definition: The energy stored in an object due to its position or state.

  • Formula: PE = mgh

• Momentum

  • Definition: The quantity of motion of a moving body, measured as a product of its mass and velocity.

  • Formula: p = mv

• Momentum-Impulse Theorem

  • States that the change in momentum of an object is equal to the impulse applied to it.

  • Formula: ext{Impulse} = ext{Change in Momentum} = F imes t

• Power

  • Definition: The rate at which work is done or energy is transferred.

  • Formula: P = rac{W}{t}

Unit 8: Electric Current and Ohm’s Law

• Electric Current

  • Definition: The flow of electric charge.

• Ohm’s Law

  • States that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance.

  • Formula: V = I imes R

• Electric Power

  • Definition: The rate at which electrical energy is transferred by an electric circuit.

  • Formula: P = V imes I

Unit 10: Waves and Sounds

• Speed of a Wave

  • Defined as distance traveled by a wave per unit time.

  • Formula: ext{Speed} = ext{Frequency} imes ext{Wavelength}

• Frequency

  • The number of oscillations or cycles per unit time.

  • Units: Hertz (Hz)

• Period

  • The time it takes for one complete cycle of a wave.

  • Formula: ext{Period} = rac{1}{ ext{Frequency}}

• Transverse Waves

  • Waves in which particle motion is perpendicular to wave motion.

  • Example: Light waves.

• Longitudinal Waves

  • Waves in which particle motion is parallel to wave motion.

  • Example: Sound waves.

Practice Problems

• Review the practice problems from each learning unit (1, 2, 3, 8, 10).

• Complete the practice problems posted on Review for Final Exam part 1 & 2.

Important Reminders

• Bring a scantron (BLUE), pencils, calculator, and formula sheets (available on Bb/Tests/Test 1 and Test 2 used for previous tests).

• Do not include any problems in the formula sheet.

1. In the SI, the symbol 'm' represents mass.

2. A unit of mass density is kg/m³.

3. Distance covered per unit of time is referred to as speed.

4. A possible unit of acceleration is m/s².

5. A freely falling object has a uniformly increasing velocity.

6. The net force on an object acted upon by two equal and opposite forces of 3.0 N is 0 N.

7. A constant net force acting on an object will produce a constant acceleration.

8. The unbalanced force acting on an object with a mass of 10 kg and an acceleration of 4 m/s² is 40 N.

9. A person weighing 150 lb on Earth would weigh 112.79 N on the Moon.

10. The unbalanced force acting on an object with a mass of 8 kg and an acceleration of 5 m/s² is 40 N.

11. The speed of the object in problem 10 after 4 s is 20 m/s.

12. The variable 'r' in the equation F = Gm₁m₂/r² is the straight-line distance between the centers of the two masses.

13. A car moving at a constant rate of 20.0 m/s for 4.0 s has an acceleration of zero.

14. The SI unit of heat is the joule.

15. If a wave has a frequency of 9 Hz, its period is 1/9 s.

16. The prefix pico- stands for 10⁻¹².

17. A system of two electrons, two protons, and five neutrons has a net charge of zero.

18. One ampere multiplied by one second is a unit of electric charge.

19. Electric power is measured in watts and can also be expressed in joules per second.

20. The electric power of a lamp carrying 2 A at 120 V is 240 W.

21. A 100-W lamp draws more current than a 60-W lamp when both are intended for 120-V operation.

22. The average current of a charge of 18 C passing through an electroplating apparatus in 3.0 min is 0.1 A.

23. A potential difference of 16 V is required to cause a current of 2.0 A to flow through a resistance of 8.0 Ω.

24. The power dissipated in a power line with a resistance of 2 ohms drawing a current of 80 A is 12,800 W.

25. When discussing electric power, we are referring to watts.

1. In the SI, m is the symbol for
   B) meter.

2. Which of the following is a unit of mass density?
   A) kg/m³

3. Distance covered per unit of time is called
   A) speed.

4. Which of the following is a possible unit of acceleration?
   A) m/s²

5. A freely falling object
   A) has a uniformly increasing velocity.

6. Two equal and opposite forces of 3.0 N act on an object. The net force on the object is
   B) 0 N.

7. A constant net force acting on an object that is free to move will produce a constant
   D) acceleration.

8. If an object of mass 10 kg has an acceleration of 4 m/s², what is the unbalanced force acting on it?
   A) 40 N

9. If a person weighs 150 lb on Earth, that person's weight on the Moon would be
   A) 112.79 N.

10. If an object of mass 8 kg has an acceleration of 5 m/s², what is the unbalanced force acting on it?
    A) 40 N

11. What is the speed of the object in problem 10 after 4 s?

    • Use the formula: Speed = Initial Speed + (Acceleration × Time)

    • Assuming initial speed is 0, Speed = 0 + (5 m/s² × 4 s) = 20 m/s.

12. The variable r that appears in the equation F = Gm₁m₂/r² is
    A) the straight-line distance between the centers of the two masses.

13. A car is moving down a freeway in a straight line at a constant rate of 20.0 m/s for 4.0 s. Its acceleration is
    C) zero.

14. The SI unit of heat is
    B) joule.

15. If a wave has a frequency of 9 Hz, it has a period of
    A) 1/9 s.

16. What does the prefix pico- stand for?
    10⁻¹²

17. A system of two electrons, two protons, and five neutrons has a net charge of
    D) zero.

18. One ampere × one second is a unit of
    D) electric charge.

19. When we talk about electric power we're talking
    C) both.

20. The electric power of a lamp that carries 2 A at 120 V is
    E) 240 W.

21. A pair of 60-W and 100-W incandescent lamps are intended for 120-V operation. Which lamp draws more current?
    B) 100-W lamp

22. A charge of 18 C passes through an electroplating apparatus in 3.0 min. What is the average current?

    • Average current = Charge/Time = 18 C/(3.0 min × 60 s/min) = 0.1 A.

23. What potential difference is required to cause 2.0 A to flow through a resistance of 8.0 Ω?

    • Use Ohm's Law: V = IR = 2.0 A × 8.0 Ω = 16 V.

24. A power line with a resistance of 2 ohms draws a current of 80 A. The power dissipated in the line is
    D) 12,800 W.

25. When we talk about electric power we're talking
    C) both.

1. In the SI, the symbol 'm' represents mass.