course phy201 ???L??????I?rassignment #021
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14:24:27 Explain how to obtain the final speed and direction of motion of a projectile which starts with known velocity in the horizontal direction and falls a known vertical distance, using the analysis of vertical and horizontal motion and vectors.
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RESPONSE --> horizontal component=horizontal v0 vertical v0=0 vertical vf=sqr(v0^2+2ads) v=sqrt(vx^2+vy^2)=magnitude then arctan(vy/vx) gives the direction
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14:24:38 ** 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. **
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RESPONSE --> ok
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14:34:04 Give 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.
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RESPONSE --> A meteor striking the moon. A baseball player hits a ball with a bat causing the ball to travel up at an angle. A billiard player hitting a cue ball to travel at a certain velocity and angle to strike another ball. The velocity and direction of travel result in the magnitude and direction and the vector components are the horizontal and vertical components that result in the magnitude and direction.
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14:34:11 ** GOOD STUDENT RESPONSE: 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.
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RESPONSE --> ok
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