Coulombs Law Flashcards
(119 cards)
1
Q
Flashcard 1:
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2
Q
front: What particles are found in the nucleus of an atom?
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3
Q
back: The nucleus contains protons
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which are positively charged subatomic particles
4
Q
Flashcard 2:
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5
Q
front: What charge does a proton carry?
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6
Q
back: A proton carries a positive charge of 1.6 × 10⁻¹⁹ coulombs.
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7
Q
Flashcard 3:
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8
Q
front: Are electric charges continuous or quantized?
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9
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back: Electric charges are quantized
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meaning they exist in discrete amounts that are multiples of the fundamental charge value.
10
Q
Flashcard 4:
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11
Q
front: What particles orbit the nucleus of an atom?
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12
Q
back: Electrons orbit the nucleus. They are negatively charged particles.
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13
Q
Flashcard 5:
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14
Q
front: What charge does an electron carry?
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15
Q
back: An electron carries a negative charge of -1.6 × 10⁻¹⁹ coulombs.
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16
Q
Flashcard 6:
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17
Q
front: How do opposite and like electric charges behave in terms of force?
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18
Q
back: Opposite charges attract each other
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while like charges repel each other.
19
Q
Flashcard 7:
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20
Q
front: What happens when a positive charge (q1) is placed near a negative charge (q2)?
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21
Q
back: They attract each other; q1 experiences a force pulling it toward q2
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and q2 experiences a force pulling it toward q1.
22
Q
Flashcard 8:
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23
Q
front: What is a net positive charge on an object?
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24
Q
back: An object with more protons than electrons has a net positive charge.
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Flashcard 9:
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front: What is a net negative charge on an object?
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back: An object with more electrons than protons has a net negative charge.
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Flashcard 10:
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front: What does it mean if the number of protons equals the number of electrons in an object?
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back: The object is electrically neutral.
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Flashcard 11:
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front: What does Coulomb's Law calculate?
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back: Coulomb's Law calculates the electric force between two point charges.
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Flashcard 12:
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front: Write the formula for Coulomb's Law.
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back: F = k * |q₁ * q₂| / r²
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Flashcard 13:
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front: What does each symbol represent in Coulomb's Law formula F = k * |q₁ * q₂| / r²?
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back: F is the electric force
k is the proportionality constant
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Flashcard 14:
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front: What is the value of the proportionality constant k in Coulomb's Law?
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back: k = 9 × 10⁹ N·m²/C²
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Flashcard 15:
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front: How else can the constant k be expressed?
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back: k = 1 / (4πε₀)
where ε₀ is the permittivity of free space.
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Flashcard 16:
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front: What is the permittivity of free space (ε₀) value?
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back: ε₀ = 8.85 × 10⁻¹² C²/(N·m²)
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Flashcard 17:
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front: How does increasing the magnitude of charges affect the electric force?
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back: Increasing the magnitude of one or both charges increases the electric force.
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Flashcard 18:
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front: How does increasing the distance between charges affect the electric force?
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back: Increasing the distance decreases the electric force
which is inversely proportional to the square of the distance.
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Flashcard 19:
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front: If the distance between two charges is doubled
what happens to the force?
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back: The force becomes one-fourth of its original value.
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Flashcard 20:
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front: What are the common units used for force
charge
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back: Force is measured in Newtons (N)
charge in Coulombs (C)
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Flashcard 21:
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front: What are the common prefixes for charge units smaller than a Coulomb?
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back: Micro (µ) = 10⁻⁶
Milli (m) = 10⁻³
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Flashcard 22:
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front: Convert 1 cm to meters.
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back: 1 cm = 0.01 meters
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Flashcard 23:
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front: Convert 1 mm to meters.
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back: 1 mm = 0.001 meters
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Flashcard 24:
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front: How do you calculate the magnitude of the electric force between a 10 µC charge and a -20 µC charge placed 25 cm apart?
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back: Convert units to Coulombs
then apply Coulomb's Law:
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F = k * |q₁ * q₂| / r² = (9 × 10⁹) * (10 × 10⁻⁶) * (20 × 10⁻⁶) / (0.25)² = 0.0288 N
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Flashcard 25:
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front: What is the formula to calculate the distance between two charges given the force?
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back: r = √(k * |q₁ * q₂| / F)
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Flashcard 26:
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front: If two charges exert a force of 15 N and their charges are q₁ = 800 nC and q₂ = 900 nC
how do you find the distance between them?
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back: Use r = √(k * q₁ * q₂ / F):
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r = √(9 × 10⁹ * 800 × 10⁻⁹ * 900 × 10⁻⁹ / 15) ≈ 0.02078 m or 2.078 cm
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Flashcard 27:
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front: How do you calculate the magnitude of identical charges that exert a known force on each other at a certain distance?
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back: q = √(F * r² / k)
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Flashcard 28:
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front: How do you convert a charge value to the number of electrons?
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back: Number of electrons = Total charge / Charge of one electron
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Flashcard 29:
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front: What is the charge of one electron?
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back: -1.6 × 10⁻¹⁹ coulombs
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Flashcard 30:
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front: How many electrons correspond to a charge of -70 µC?
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back: Number of electrons = |-70 × 10⁻⁶| / (1.6 × 10⁻¹⁹) ≈ 4.375 × 10¹⁴ electrons
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Flashcard 31:
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front: How do you convert a number of protons to electric charge?
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back: Total charge = Number of protons * Charge of one proton
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Flashcard 32:
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front: What is the charge of one proton?
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back: +1.6 × 10⁻¹⁹ coulombs
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Flashcard 33:
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front: If a metal sphere has 5 × 10¹⁴ protons and 8 × 10¹⁴ electrons
what is the net charge?
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back: Net charge = (5 × 10¹⁴ - 8 × 10¹⁴) * 1.6 × 10⁻¹⁹ = -4.8 × 10⁻⁵ C or -48 µC
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Flashcard 34:
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front: When is the net charge positive and when is it negative?
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back: The net charge is positive if the number of protons exceeds electrons; negative if electrons exceed protons.
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Flashcard 35:
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front: Describe the forces on a 200 µC charge at x = -4 m from a 100 µC charge at the origin and a -50 µC charge at x = 2 m.
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back: The 200 µC charge experiences an attractive force towards the negative 50 µC charge and a repulsive force from the positive 100 µC charge. The net force is the vector sum of these two.
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Flashcard 36:
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front: How do you calculate net force on a charge from multiple other charges?
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back: Calculate forces from each charge individually using Coulomb's Law
then add vectorially.
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Flashcard 37:
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front: Calculate the force on the 200 µC charge due to the 100 µC charge at 4 meters away.
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back: F = (9 × 10⁹) * (200 × 10⁻⁶) * (100 × 10⁻⁶) / 4² = 11.25 N
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Flashcard 38:
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front: Calculate the force on the 200 µC charge due to the -50 µC charge at 6 meters away.
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back: F = (9 × 10⁹) * (200 × 10⁻⁶) * (50 × 10⁻⁶) / 2² = 11.25 N
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Flashcard 39:
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front: What is the net force on the 200 µC charge from both the 100 µC and -50 µC charges?
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back: Net force = 11.25 N + 11.25 N = 22.5 N (in the positive x direction).
