1 / 12

Electrostatics

Part 3. Electrostatics. Electric Field vs Gravitational Field. The electric field can push AND pull charges Because there are two types of charges (+ and -) The gravitational field can only pull Only positive masses. Cause of Electric Field. Charges cause an electrical field.

anais
Télécharger la présentation

Electrostatics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Part 3 Electrostatics

  2. Electric Field vs Gravitational Field • The electric field can push AND pull charges • Because there are two types of charges (+ and -) • The gravitational field can only pull • Only positive masses

  3. Cause of Electric Field • Charges cause an electrical field. • Each charge creates its own electric field in the surrounding space. • Electric Field is a vector quantity • Has magnitude and direction • Use Electric Field lines(lines of force) to show the Electric Field

  4. Drawing the Electric Field • Electric field direction from charge that creates the field: • Away from positive charge • Toward negative charges • The lines begin on positive charges and end on negative charges. • Draw lines perpendicular to charge • Lines never cross

  5. Calculating the Electric Field • Electric field strength: • The closer to the charge, the stronger the field • The closer the field lines, the stronger the field • The farther away, the weaker the field

  6. Calculating the Electric Field • Electric field strength: • The number of lines are proportional to strength • The more lines the stronger the field

  7. Calculating the Electric Field • Electric field strength: (quantitative) E = kq/d2 • Depends on Charge and distance • E = Electric field strength (Newton/Coulomb, N/C) • k = 9.0 x 109 Nm2/C • q= charge causing the field (Coulomb, C) • d or r = distance (meters, m)

  8. Practice Problem 1 • A fly accumulates 3.0 x 10-10 C of positive charge as it flies through the air. What is the magnitude and direction of the electric field at a location 2.0 cm away from the fly? q = 3.0 x 10-10C d or r = 2.0 cm = _____ m E = ? equation E = kq/ r2 E = (9.0 x 109)(3.0x10-10) (0.020)2 E = 6750 N/C 0.020

  9. Charges in Electric Field Electric Field = force exerted on positive charge If +q = force in same direction (pull) of the field If -q = force in opposite direction (push) of the field

  10. The electric field… • The strength of the electric field… E = F/q • E = strength of the field (Newton/Coulomb, N/C) • F = Force exerted on charge in field (Newton, N) • q = charge (Coulomb, C) that sits in the field; experiences the force

  11. Practice Problem 2 A charge of -2.0 x10-6C is placed in a uniform electric field of strength 5000 N/C that points downward. What is the magnitude and direction of the force experienced by this charge?

  12. Practice Problem 2 A charge of -2.0 x10-6C is placed in a uniform electric field of strength 5000 N/C that points downward. What is the magnitude and direction of the force experienced by this charge? E = F / q 5000 N/C= F / (-2.0 x 10-6C) (-2x10-6 )(5000)=F -0.01N=F magnitude of the force direction? - 2 charge, the force on the electron is opposite the field!

More Related