Unit 1: The first thing we did, was compare mass, angle and length to a pendulum. We did this by doing the "Period of A Pendulum Lab", and discovered that angle and length have a direct relationship, whereas mass and periods have an inverse relationship. All of these reltionships can be drawn out on a d-t graph, which measures distance vs. time. Next we learned the 5 different types of graphs. 1) no relationship [line is horizontal], 2) directly proportionate [linear diagonal starting from origin], 3) inversely proportional [a curved line starting at a relatively high and ending at a relatively low distance], 4) proportional to the square of x [the right half of a U shape] and 5) proportional to the root of x [the top left side an o]. A few more things we learned (and didn't go into great depth on) are scientific notation, the difference between accuracy and precision and dimmensional analysis.
Unit 2: Unit two was all about kinematics and motion maps. Using many key words, we learned how to graph the motion of an object given its' description. Some key words include scalar, vectors, displacement, instantaneous speed, instantaneous velocity, constant velocity, acceleration, avg. speed, avg. velocity, velocity, and position. The most important thing we learned, is probably the 3 graphing rules; The slope of a DT graph equals velocity, the slope of a VT graph is acceleration and the area under the curve of a VT graph is displacement.
Unit 3: Unit three was still about kinematics, but focused on a certain type of it, acceleration. We learned from the acceleration activity lab that the relationship between position and time is position equal time squared. After knowing how to graph a VT and DT graph from the previous unit, we learned how to create an acceleration graph using the VT graph. If the slope of a VT graph is going negative at a constant rate, then there is a negative horizontal line in the AT graph. Same thing for if it is going at a positive constant rate, the slope would be horizontal at a positive velocity. If there is no slope in the VT graph, this means that it is not accelerating, which means there is a horizontal line lying at zero on the AT graph. We also did a couple of labs on free falling objects. When you are throwing an object in the air, it is accelerating downward so the velocity slows down the higher it goes up. When the object is at the highest point, it is no longer accelerating, so the acceleration is zero. Then it is falling back down at a relatively similar time to when it was thrown up. The object accelerates as it moves closer to the starting position. So when you throw the object and when you catch it is when the velocity is the fastest. Lastly, we learned that earth has a gravitational pull of about 9.8 m/s^2, which is why the object slows down as you throw it up. Because you are throwing it up (away from the ground), gravity wants to pull it back down, so the object is accelerating in the negative direction, slowing it down to a stop.
That's about it, we learned all this in 10 days; it was a whirlwind!!
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| The earth moves at a constant velocity of 107,300 km/h around the sun. It does not accelerate in the positive or negative direction. |
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