Electrostatics Problems: Charges, Forces, and Fields
Iron atoms have been detected in the sun’s outer atmosphere, some with many of their electrons stripped away. What is the net electric charge (in coulombs) of an iron atom with 26 protons and 7 electrons? Be sure to include the algebraic sign (+ or -) in your answer.
Four identical metallic objects carry the following charges: +1.6, +6.2, -4.8, and -9.4 micro Coulombs. The objects are brought simultaneously into contact, so that each touches the others. Then they are separated. (a) What is the final
Read MoreMagnetic Fields and Forces: Key Concepts and Applications
Magnetic Force on a Moving Charge
The magnitude of the force is proportional to the value of the load and the magnitude of the velocity with which it moves. The direction of the force depends on the direction of that velocity.
Helical Path
If the charged particle has a velocity component parallel to the magnetic field and one perpendicular, it follows a helical path.
Conductor Inside a Magnetic Field
The magnetic field interacts with each of the charged particles whose motion produces the current. The
Read MoreFundamental Laws of Physics: Units 1-3
Unit 1: Newton’s Laws of Motion
Newton’s First Law (Law of Inertia)
An object in motion stays in motion unless acted upon by an unbalanced outside force. For example, a ball sitting on a table will not move until someone hits it.
- Distance: Total movement.
- Displacement: Direct line movement (change in position).
Newton’s Second Law
F = ma (Force equals mass times acceleration). A wooden ball moves faster in space than a brass ball.
Newton’s Third Law
For every action, there is an equal but opposite reaction.
Read MoreOptical Instruments and Phenomena: A Comprehensive Study
Periscope
Periscopes use isosceles rectangular glass prisms with a critical angle of approximately 43 degrees. The light inside the glass normally follows the path shown in the accompanying figure.
Pinhole Cameras
The simplest optical device is a pinhole camera, which is a closed box with a hole in one wall. It always produces real and inverted images, and its gain is given by A = y’ / s’.
Microscope
A microscope is used to see a greatly magnified image of a very small object at a short distance. It
Read MoreKey Equations and Concepts in Physics
Angular Motion
Equations of angular motion are relevant wherever you have rotational motions around an axis. When the object has rotated through an angle of θ with an angular velocity of ω and an angular acceleration of α, then you can use these equations to tie these values together.
You must use radians to measure the angle. Also, if you know that the distance from the axis is r, then you can work out the linear distance traveled, s, velocity, v, centripetal acceleration, ac, and force, Fc. When
Read MorePhotogrammetry: Image Formation and Distortion Analysis
Maintaining Adequate Air Coatings
In order to maintain adequate air coatings, which of the following statements are correct?
- With flying height constant, the value of the photogrammetric base increases in proportion to the altitude of the relief.
- Holding the value of the photogrammetric base constant, the flight height increases in proportion to the height of relief.
- Keeping the flying height constant, the value between flight lines decreases in proportion to the altitude of the terrain.
- Keeping the