course Phy 121 020. `query 20 *********************************************
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Given Solution: `a** If we add the x components of the original two vectors we get the x component of the resultant. If we add the y components of the original two vectors we get the y component of the resultant. ** Self-critique (if necessary): OK Self-critique rating #$&* OK ********************************************* Question: `qExplain how we get the components of a vector from its angle and magnitude. Your solution: x=magnitude*costheta and y=magnitude*sintheta Confidence rating #$&*: 3
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Given Solution: `a** To get the y component we multiply the magnitude by the sine of the angle of the vector (as measured counterclockwise from the positive x axis). To get the x component we multiply the magnitude by the cosine of the angle of the vector (as measured counterclockwise from the positive x axis). ** &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Self-critique (if necessary):OK Self-critique rating #$&* OK ********************************************* Question: `qprin phy, gen phy 7.02. Const frict force of 25 N on a 65 kg skiier for 20 sec; what is change in vel? Your solution: -25*20= -500N/65kg= -7.7m/s^2*s/kg Confidence rating #$&*: 3
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Given Solution: `aIf the direction of the velocity is taken to be positive, then the directio of the frictional force is negative. A constant frictional force of -25 N for 20 sec delivers an impulse of -25 N * 20 sec = -500 N sec in the direction opposite the velocity. By the impulse-momentum theorem we have impulse = change in momentum, so the change in momentum must be -500 N sec. The change in momentum is m * `dv, so we have m `dv = impulse and `dv = impulse / m = -500 N s / (65 kg) = -7.7 N s / kg = -7.7 kg m/s^2 * s / kg = -7.7 m/s. Self-critique (if necessary): OK Self-critique rating #$&* OK "
course Phy 121 020. `query 20 *********************************************
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Given Solution: `a** If we add the x components of the original two vectors we get the x component of the resultant. If we add the y components of the original two vectors we get the y component of the resultant. ** Self-critique (if necessary): OK Self-critique rating #$&* OK ********************************************* Question: `qExplain how we get the components of a vector from its angle and magnitude. Your solution: x=magnitude*costheta and y=magnitude*sintheta Confidence rating #$&*: 3
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Given Solution: `a** To get the y component we multiply the magnitude by the sine of the angle of the vector (as measured counterclockwise from the positive x axis). To get the x component we multiply the magnitude by the cosine of the angle of the vector (as measured counterclockwise from the positive x axis). ** &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Self-critique (if necessary):OK Self-critique rating #$&* OK ********************************************* Question: `qprin phy, gen phy 7.02. Const frict force of 25 N on a 65 kg skiier for 20 sec; what is change in vel? Your solution: -25*20= -500N/65kg= -7.7m/s^2*s/kg Confidence rating #$&*: 3
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Given Solution: `aIf the direction of the velocity is taken to be positive, then the directio of the frictional force is negative. A constant frictional force of -25 N for 20 sec delivers an impulse of -25 N * 20 sec = -500 N sec in the direction opposite the velocity. By the impulse-momentum theorem we have impulse = change in momentum, so the change in momentum must be -500 N sec. The change in momentum is m * `dv, so we have m `dv = impulse and `dv = impulse / m = -500 N s / (65 kg) = -7.7 N s / kg = -7.7 kg m/s^2 * s / kg = -7.7 m/s. Self-critique (if necessary): OK Self-critique rating #$&* OK "