* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download - Cross Roads ISD
Inertial frame of reference wikipedia , lookup
Flow conditioning wikipedia , lookup
Coriolis force wikipedia , lookup
Sagnac effect wikipedia , lookup
Classical mechanics wikipedia , lookup
Brownian motion wikipedia , lookup
Relativistic angular momentum wikipedia , lookup
Hunting oscillation wikipedia , lookup
Fictitious force wikipedia , lookup
Minkowski diagram wikipedia , lookup
Seismometer wikipedia , lookup
Equations of motion wikipedia , lookup
Rigid body dynamics wikipedia , lookup
Frame of reference wikipedia , lookup
Specific impulse wikipedia , lookup
Surface wave inversion wikipedia , lookup
Matter wave wikipedia , lookup
Classical central-force problem wikipedia , lookup
Newton's laws of motion wikipedia , lookup
Time dilation wikipedia , lookup
Length contraction wikipedia , lookup
Faster-than-light wikipedia , lookup
Centripetal force wikipedia , lookup
Derivations of the Lorentz transformations wikipedia , lookup
Primetime What do we use to measure distance and time? Name the steps in the scientific method. TEKS 2B,C, 4A,B,C,E Motion A mass or masses moving in different directions with different speeds is motion One dimensional motion is the simplest form of motion (object only travels in one direction); ex: train traveling on the tracks Motion takes place over time and depends on the frame of reference; ex: while the train moves on the tracks, the earth is spinning on its axis and it’s rotating around the sun Frame of Reference When modeling a situation like the train moving, choose a simple frame of reference like the two stations the train is traveling between You can choose any frame of reference you want , but you must be consistent Primetime If you were to walk from here to the baseball field would your displacement and distance be the same? Why? If you were to walk to the lunch room and back would your displacement and distance be the same? Why? Distance vs. Displacement Distance is how far an object travels in total Displacement: length of the straight line drawn from object’s initial position to its final position; how far the object is from its starting point Ex: A gecko was initially at 22cm and moved to 85cm. What was the gecko’s displacement? Gecko’s Displacement xi = initial position xf = final position ∆x = displacement ∆ x = xf – xi ∆ x = 85cm – 22cm = 63cm Displacement is NOT always equal to distance traveled; ex: room walk Displacement Displacement can be positive or negative Sign tells you the direction Positive:object is moving to the right Negative: object is moving to the left Ex: Table 2-1 Velocity Velocity is like speed but also has a direction associated with it Average velocity is displacement over time or d/t Another way to write the formula is as follows: Formula Average Velocity vavg = average velocity ∆ x = displacement ∆ t = change in time vavg = ∆ x/ ∆ t = (xf – xi)/(tf – ti) Average velocity can be positive or negative and tells us the direction Time will NOT be negative, ever Velocity Example You travel to a friend’s house 370km to the west. If you left your house at 10am and arrived at 3pm, what was your average velocity? Example, cont. Known Unknown xi = 0km ?vavg xf = 370km west ti= 10am tf = 3pm vavg = ∆ x/ ∆ t = (xf – xi)/(tf – ti) vavg = (-370km – 0km)/(5hrs) vavg = -370km/5hr vavg = -74km/hr or 74km/hr west Primetime Find the velocity of a person that traveled 5m North, 8m South, and 10m North in 64seconds. Sample Problem 2A Known Unknown ∆ t = 137s ?∆x vavg= 6.02m/s east vavg = ∆ x/ ∆ t so rearranging to get ∆ x by itself we get ∆ x = vavg ∆ t Sample, cont. ∆ x = (6.02m/s)(137s) Seconds cancel out because one is on top of fraction and other on bottom, leaving meters ∆ x = 825m east Speed vs. Velocity Velocity and speed are not the same Speed only has a magnitude (value) Velocity has both a magnitude and direction Velocity can be found graphically as on figure 2-5 in your book Instantaneous Velocity Defined as the exact velocity at a specific time Instantaneous velocity may not be the same as average velocity Assignment Practice 2A p.44 1-6 Section Review p.47 1-6