#$&* course Phy 121 12/15 10 am 021. `query 21
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Given Solution: `a** The horizontal velocity is unchanging so the horizontal component is always equal to the known initial horizontal velocity. The vertical velocity starts at 0, with acceleration thru a known distance at 9.8 m/s^2 downward. The final vertical velocity is easily found using the fourth equation of motion. We therefore know the x (horizontal) and y (vertical) components of the velocity. Using the Pythagorean Theorem and arctan (vy / vx) we find the speed and direction of the motion. ** &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Self-critique (if necessary): I feel so dumb that I forgot about the rule that the horizontal velociy doesn't change! I usually remember that first thing, because it always makes the question easier after reading through it one time. I also forgot to mention the Pythagorean Theorem, I guess I just assumed we knew the value of the vector. ------------------------------------------------ Self-critique Rating:3 ********************************************* Question: `qGive at least three examples of vector quantities for which we might wish to find the components from magnitude and direction. Explain the meaning of the magnitude and the direction of each, and explain the meaning of the vector components. YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY Your solution: 1) Vector quantity: 16 m/s Direction: 60 degrees counterclockwise. x component would = magnitude * cos(angle) = 16 * cos(60) = 8 y component would = magnitude * sin(angle) = 16 * sin(60) = 13.9 The magnitude represents the ""c"" side of the Pythagorean Theorem. It is the straight line distance between the two points (usually one of which being the origin). The direction allows you to know which quadrent the vector is in, which makes a huge difference in the vector values. 2) Vector quantity: 5 m/s Direction: 110 degrees counterclockwise x component would = magnitude * cos(angle) = 5 * cos(110) = -1.7 y component would = magnitude * cos(angle) = 5 * sin(110) = 4.7 The magnitude represents the ""c"" side of the Pythagorean Theorem. It is the straight line distance between the two points (usually one of which being the origin). The direction allows you to know which quadrent the vector is in, which makes a huge difference in the vector values. 3) Vector quantity: 24 m/s Direction: 340 degrees counterclockwise x component would = magnitude * cos(angle) = 24 * cos(340) = 22.6 y component would = magnitude * sin(angle) = 24 * sin(340) = -8.2 The magnitude represents the ""c"" side of the Pythagorean Theorem. It is the straight line distance between the two points (usually one of which being the origin). The direction allows you to know which quadrent the vector is in, which makes a huge difference in the vector values. confidence rating #$&*: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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Given Solution: `a Examples might include: A force acting on an object causing it to move in an angular direction. A ball falling to the ground with a certain velocity and angle. A two car collision; velocity and momentum are both vector quantities and both important for analyzing the collision.. The magnitude and directiohn of the relsultant is the velocity and direction of travel. The vector components are the horizontal and vertical components that would produce the same effect as the resultant. &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Self-critique (if necessary): I did not realize it was asking for an entire situation linked example, I just gave values for an example. ------------------------------------------------ Self-critique Rating:3 " Self-critique (if necessary): ------------------------------------------------ Self-critique rating: " Self-critique (if necessary): ------------------------------------------------ Self-critique rating: #*&!