# Previous answers scalcet7 33035mi a mass on a spring

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5. 7/7 points | Previous Answers SCalcET7 3.3.035.MI. A mass on a spring vibrates horizontally on a smooth level surface (see the figure). Its equation of motion is where t is in seconds and x is in centimeters. (a) Find the velocity and acceleration at time t . (b) Find the position, velocity, and acceleration of the mass at time t = 2 π / 3 . = \$\$4√3 = \$\$−4 x ( t ) = 8 sin t , v ( t ) = \$\$8 cos ( t ) a ( t ) = \$\$−8 sin ( t ) x 2 π 3 v 2 π 3
= \$\$−4√3 In what direction is it moving at that time? Since < 0, the particle is moving to the left . a 2 π 3 v 2 π 3
6. 5/5 points | Previous Answers SCalcET7 3.3.038. An object with weight W is dragged along a horizontal plane by a force acting along a rope attached to the object. If the rope makes an angle θ with the plane, then the magnitude of the force is where μ is a constant called the coefficient of friction . (a) Find the rate of change of F with respect to θ . F = µ W μ sin θ + cos θ
(b) When is this rate of change equal to 0?
(c) If W = 70 lb and μ = 0.5 , draw the graph of F as a function of θ .