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Wright State University Department of Mechanical and Materials Engineering ME 213, Winter 2011 ME 213 DYNAMICS: MIDTERM EXAM 1 Open Book, Closed Notes, DO NOT write on this sheet, Show all work Problem 1 (15 points): The motion of a particle is defined by the relation 𝑥 = 15𝑡 3 − 19𝑡 2 + 3𝑡 + 7, where x and t are expressed in meters and seconds, respectively. Determine the position and the velocity when the acceleration of the particle is equal to zero. Problem 2 (30 points): Block B starts from rest and moves downward with a constant acceleration. Knowing that after slider block A has moved 450 mm its velocity is 5 m/s, determine the accelerations of A and B, and the velocity of B after 1.2 s. Problem 3 (40 points): A 22-kg package is at rest on an incline when a force P is applied to it. Determine the magnitude of P if 8 s is required for the package to travel 6 m up the incline. The static and kinetic coefficients of friction between the package and the incline are both equal to 0.25. Problem 4 (15 points): Rod OA oscillates about O in a horizontal plane. The motion of the collar of mass m is defined by the relations 𝜋𝑡 𝑟 = 𝑎 + 𝑏 cos ( 2 ); 𝜃 = 𝜋(𝑡 2 + 𝑐𝑡) Determine the radial and transverse components of the force exerted on the collar.