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This lab aims to solve a problem using Kinematics and Energy Conservation principles. Conduct experiments involving a ball drop, ballistic pendulum, and metal ball acceleration to explore velocity, moment of inertia, and conservation laws. Compare results from Kinematic and Energy approaches.
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Purpose • Solve a problem by using • Kinematics (Newton’s Laws, Equations of Motion) • Energy/Momentum Conservation. • Use techniques learned in earlier labs: • Measuring techniques • Error calculation • Statistics
A simple example of kinematic versus energy conservation approaches. Dropping a ball from a height of 1m. Calculate the velocity just before the impact on the floor. vo= 0 y = 0 h=1m y vf= ?
Kinematic Approach y = 0 y
Energy Approach y = 0 Kinetic Energy Potential Energy y
Ballistic Pendulum Apparatus Pendulum that catches the ball and is able to swing after the impact. Spring loaded apparatus that “shoots” metal ball.
A. Determine the Speed of the Metal Ball Using a Kinematic Approach Idea: 1) Remove the pendulum part and simply shoot the ball horizontally off the table 2) Measure the horizontal and vertical distances from launch to impact on the floor. 3) Calculate vo. vo x y
vo B. Determine the Speed of the Metal Ball Using a Momentum Conservation and Energy Conservation Approach • Idea: • Shoot the metal ball into the pendulum so that the metal ball gets stuck in it. • Measure the maximum angle the pendulum will swing up after the impact. • Use conservation of angular momentum and conservation of energy to • determine vo. L conserved v Before impact: After impact:
v Energy conserved Qmax At maximum of the swing: After impact:
Determining the Moment of Inertia of Pendulum with Ball (Isystem) 1) Disconnect the pendulum and reattach it on the other side so that it can swing freely. 2) Let the pendulum swing (with the ball in it) and measure the period of oscillation. 3) Determine the moment of inertia I using this formula: Hint: You can get lcm by balancing the pendulum on the center of mass: lcm