Experiment 4 Conservation of Energy Experiment Goals Verify

Experiment 4 Conservation of Energy

Experiment Goals Verify “KE + PE = Constant” Methods of Storing Potential Energy (Spring & gravitational potential) Work-Kinetic Energy Theorem Work = FDx = D(K. E. ) Determine Spring Constant

Part 1: Initial Setup Measure mass of blue glider Measure mass of Hanger + 2 Washers

Part 2 : Conservation of Energy in a System with Falling Weight With Time, PE while KE However PE + KE = constant 1 m

Work-Kinetic Energy Theorem For a constant applied force Work = FDx [N-m or kg m/s 2 - m] K. E. = ½ mv 2 [kg-m 2/s 2] same units ! The tension in the string applies a constant force over some Dx. Measure a and Dx with sonar … Work =Ma. Dx The change in the kinetic energy from the beginning to the end of that Dx should equal the Work Measure vi and vf with sonar … DK. E. = ½ m(vf 2 -vi 2)

Part 3(a): Determining Spring Constant Plot “W” vs “x”. The slope will give Spring Constant “k” X-intercept will give xeq

Part 3(b) : Conservation of Energy in a System with Stretched Spring The Stored Potential Energy In Stretched Spring is converted into Kinetic Energy of Glider Is energy conserved? Limits based on experiment?

Summary n Conservation of Energy u Glider and Gravity & Glider and Spring F Is Energy conserved? What is E? F Does expected value fall in uncertainty range of your experimental measurements n What is the spring constant?