Question

Practice Problems 12-12. Determine the total time required for a car to travel 1km along a straight road if it starts from rest (position 1), reaches a maximum speed at some intermediate point (position 2) and then stops at the end of the road (position 3). The car accelerates at 1.5m/s2 and decelerates at 2m/s. Hint: Draw a straight line with three positions marked on it. Write kinematics equations corresponding to positions 1-2 and 2-3, and solve the resulting equations simultaneously. Answers: 12-27.6s, t23-20.7s, t-48.7s. Example: A metallic particle is subjected to the influence of a magnetic field as it travels downward 100 mm I through a fluid that extends from plate A to plate B. If the particle is released from rest at the midpoint C, s=100mm, and the acceleration is a-4s m/s, where s is in meters, determine the velocity of the particle when it (x2 - c2)/2 reaches plate B, s-200mm, and the time it takes to travel from C to B. Answers: VB-0.346m/s; t-0.658s Particle Kinematics 21

Answer 1