Problem 1: A car door is inadvertently left slightly open when the brakes are applied to give the car a constant rearward acceleration a . Derive expressions for the angular velocity of the door as it swings past the 90 ± position and the components of the hinge reactions for any value of ± . The mass of the door is m , its mass center is a distance r G from the hinge axis O , and the radius of gyration about O is k O. Ans: Problem 2: The two slender bars, each having a mass of 4 kg, are hinged at B and pivoted at C . If a horizontal impulse is applied to the end A of the lower bar during an interval of 0.1 s during which the bars are still essentially in their vertical rest positions, compute the angular velocity ² 2 of the upper bar immediately after the impulse. Ans: 2 = 2.50 rad/s Problem 3: The 2-lb piece of putty is dropped 6ft onto the 18-lb block initially at rest on the two springs, each with a stiffness k = 3 lb/in. Calculate the additional deflection ³ of the springs due to the impact of the putty, which adheres to the block
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