Static Electricity Legacy Problem #1 Guided Solution
Problem*
Determine the quantity of charge on …
- A plastic tube which has been rubbed with animal fur and gained 3.8x109 electrons.
- A vinyl balloon which has been rubbed with animal fur and gained 1.7x1012 electrons.
- An acetate strip which has been rubbed with wool and lost 7.3x108 electrons.
Audio Guided Solution
Objects are charged when they have an imbalance in the number of protons and electrons. If an object has more electrons than protons, then it has an overall negative charge, and if an object has more protons than electrons, it has an overall positive charge. The actual quantity of charge can be calculated knowing that the charge of an electron and a charge of the proton is the same. It's 1.60 times 10 to the negative 19th Coulombs. The only difference being that a proton has a positive type charge and an electron a negative type charge. In this problem, you're given the amount of electrons that have been gained or lost when two objects are rubbed together. In knowing this amount of electrons gained or lost, you can calculate the quantity of charge. Simply take the amount of electrons that have been gained and multiply by the charge of a single electron. 1.60 times 10 to the negative 19th Coulombs. Or, if electrons have been lost, take the number of electrons that have been lost and multiply it by that same number, 1.60 times 10 to the negative 19th Coulombs.
Solution
- 6.1x10-10 C (of negative charge)
- 2.7x10-7 C (of negative charge)
- 1.2x10-10 C (of positive charge)
Habbits of an Effective Problem Solver
- Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
- Identify the known and unknown quantities; record them in an organized manner. A diagram is a great place to record such information. Equate given values to the symbols used to represent the corresponding quantity - e.g., \(Q_1 = 2.4 \unit{\micro\coulomb}\); \(Q_2 = 3.8 \unit{\micro\coulomb}\); \(d = 1.8 \unit{m}\); \(F_\text{elect} = \colorbox{gray}{Unknown}\).
- Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
- Identify the appropriate formula(s) to use.
- Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.
Read About It!
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