CH5_braunsteinc

After reading each passage, imagine that you are a journalist. Newspaper headlines have to grab the reader’s attention, and they must capture the essence of the story in one line. In addition, the first paragraph (usually only 2 – 4 sentences) includes all of the major points, with the rest of the article fleshing out those points fully. Your job is to generate the headline and first paragraph only. Do this for each concept presented in the passages that you are assigned to read (generally, each webpage from TPC).
 * Method 5: Headline Technique**

=Lesson 1:=

lesson 1- A:
speed and velocity of circular motion! uniform circular motion is an object moving in a circular path at constant speed. the average speed of an object going in circular motion is distance (or circumference) divided by time (or period). The velocity of something in circular motion is constantly changing, the vector of it goes out tangential to the circle.

lesson 1- B:
an object in circular motion is always accelerating! An object moving in a constant speed is accelerating because the direction of its velocity vector is changing. The acceleration of an object is in the direction of its velocity change, also objects moving in constant speed circles accelerate towards the center of the circle.

lesson 1- C:
An object in circular motion has an inward seeking force- the centripetal force! The centripetal force changes the objects direction. Via displacement, centripetal force changes the velocity vector. The force is perpendicular to the tangential velocity so it can change the direction without changing the speed.

lesson 1- D
Centripetal...centrifugal...what's the difference?! People often confuse centripetal and centrifugal, however centrifugal means away from the center, not towards. Many people also think there is a centrifugal force away from the center of the circle...wrong! There is no such thing as centrifugal force, only centripetal force exists!!!

lesson 1- E
Too many equations? Never! Dealign with circles causes the equations we're so used to to change. Acceleration= 2piR^2/time. Remember, the centripetal force always goes towards the center of the circle and is always positive!!

=lesson 2=

lesson 2- A
newton's second law-revisited

=lesson 4=

lesson 4- D:
what does it mean to be weightless? weightlessness is a sensation experienced by an individual when there are no external objects touching one's body and exerting a push or pull upon it whats the difference between contact and non contact forces? contact forces result from two objects actually touching each other noncontact forces do not require two objects to be in contact to exert a force, it can work over a distance. these are often called action-at-a-distance forces what causes weightlessness? it occurs when there are no contact forces acting on an object, therefore the only force acting is gravity, a non contact force, so it feels like there are no forces acting on the object why are people weightless in orbit? there is still gravity acting on them and no outside contact forces, so they feel weightless

lesson 4- E:
how are energy and satellites related?  **work-energy theorem**. Simply put, the theorem states that the initial amount of total mechanical energy (TMEi) of a system plus the work done by external forces (Wext) on that system is equal to the final amount of total mechanical energy (TMEf) of the system. The mechanical energy can be either in the form of potential energy (energy of position - usually vertical height) or kinetic energy (energy of motion). The work-energy theorem is expressed in equation form as **KEi + PEi + Wext = KEf + PEf****can be simplified to** as a satellite orbits earth, its total mechanical energy remains the same. for a circular orbit, kinetic and potential remain the same. for an elliptical orbit, the kinetic and potential energy changes; as one goes up the other goes down and vice versa.
 * KEi + PEi = KEf + PEf **