Electrostatics

• A charged object can create an electric field around it.
• The electric field is the force per unit charge exerted on an isolated positive test charge placed at any point.
• The strength of the electric field is measured by its potential difference (V) or voltage, which is defined as the work done per unit charge to move a positive test charge from one point to another.
• Electric fields are represented by arrows, with the length of the arrow representing the magnitude of the field strength and the direction indicating the direction of the force that would be experienced by a positive test charge.
• Like charges repel, while opposite charges attract.
• Electric fields are represented using arrows that show direction and length proportional to magnitude.
• Electrostatics involves forces between charged objects. Learn about charging by conduction, induction, and friction along with an intro to electrostatics.
• Electrostatics is the physics that deals with the interactions of static (non-moving) charges.

  • Positive charges attract negative charges and repel other positive charges
  • Negative charges attract positive charges and repel other negative charges
• Static electricity involves charged objects that are static, which means not moving.
• Static-charged objects create an electric field that interacts with other charged objects around them.
• When there is a consistent supply of electrons (negative terminal) and another area for those electrons to flow (positive terminal) you get a current.
• A current is a flow of electrons.
• While a static charge creates an electric field, a moving charge or current creates a magnetic field around it.
• Lightning is the result of clouds charging and positive and negative strike lightning is a result of grounding that charge
• Coulomb's Law: Calculating the Electrostatic Force
• If the charge of one of the particles is doubled, the new force is 1/4 times different compared to the original.
• Two charged particles are an unknown distance away from each other.
• If the distance between the particles is halved and the charges of both particles are doubled, the new force is 1/4 times different compared to the original.
• The force between charges of 10.0 µC and -50.0 µC located 0.20 m apart is 56.5 N.
• The magnitude of the charge on each sphere is 4.33 x 10^-6 C.
• If the charge of both particles is doubled, the new force is 16 times different compared to the original.
• Two spheres with identical charges are 0.75 m apart, and the force between them is 0.30 N.
• If the distance between the particles is doubled, the new force is 2 times different compared to the original.
• The electrostatic force between two objects, +13 μC and -22 μC which are 0.055m apart (μC = 1 x 10^-6 C) is an attraction.
• If the charge on each object is doubled and the distance between them is quadrupled, the force will be affected proportionally.
• The electrostatic force between two objects is 6.4 N when the charges are -4.5 x 10^-6 C and -8.8 x 10^-6 C.
• Electrical force is proportional to distance, with a force going to 1/4 when distance gets bigger.
• The electrostatic force between two objects of -14 x 10^-6 C and -22 x 10^-6 C that are 0.86 m apart is also an attraction.
• The better the insulator between the objects, the lower the value of “k”, with a k value of 9.0 x 10^9 Nm^2/C^2 for air as the insulator.
• When the distance between two objects is 0.86 m, the force is 6.4 N.
• If two 4.0x10^-14 C pieces of dust exert an electrostatic force of 2.0 x 10^-12 N on each other, they must be separated by 0.0027 m.
• Going from 2m to 1m is half the distance, so the force between these charges can be found using Coulomb's Law and multiplying it by the 15N original force.
• A PVC pipe becomes negatively charged by gaining protons.
• Electrons can be lost to become positively charged.
• A -60 C charge and a +20 C charge are 2 meters apart and would attract each other.
• An attraction force of 1.1 N is exerted between two charged objects when they are 0.43 m apart, with one object having a charge of -5.7 x 10^-6 C.
• Electrons are gained when something becomes negatively charged.
• A wool cloth becomes positively charged by gaining electrons.
• Protons are not transferred during charging.
• Most Coulomb's Law problems will involve charges, distances, and forces that result.