Lab 8 (1)

Table 3 - Elastic Collisions Q&A 1) When two carts moving toward each other have the same mass and the same speed, they stop when they collide and stick together. What happens to each cart’s momentum? Is momentum conserved? Explain. -In an inelastic collision as described above, momentum is conserved but not kinetic energy. Since, the two objects stick together following collision they move together at the same speed. 2) Kinetic Energy is not conserved in inelastic collisions. For one of the collisions, calculate the percentage of the kinetic energy that is lost in the collision. Where does this energy go? 𝑚₁?₁ + 𝑚₂?₂ = 𝑚₁?₁ + 𝑚₂?₂ ?𝐸𝑖 = 1/2(271. 4 × 0)² + 1/2(273 ×− 0. 612)² = − 51. 125? ?𝐸𝑓 = 1/2(271. 4 ×− 0. 338)² + 1/2(273 ×− 0. 338)² = − 31. 097? ∆?𝐸 (?𝑜??) = − 31. 097 + 51. 125 = 20. 028? -Some of it gets converted to thermal energy. 3) Kinetic Energy is not conserved in inelastic collisions but is conserved in ideal elastic collisions. For one of the collisions, calculate the percentage of the kinetic energy that is lost in the collision. Was kinetic energy conserved? Explain your results. 𝑚₁?₁ + 𝑚₂?₂ = 𝑚₁?₁ + 𝑚₂?₂ ?𝐸𝑖 = 1/2(271. 4 × 0)² + 1/2(273 ×− 0. 603)² = − 49. 63? ?𝐸𝑓 = 1/2(271. 4 ×− 0. 752)² + 1/2(273 ×− 0. 003)² = − 76. 74? ∆?𝐸 (?𝑜??) = − 76. 74 + 49. 63 = − 27. 10? -The object is slowing down, as can be determined by the negative change in kinetic energy. However, due to the change in kinetic energy not being equal to zero kinetic energy was not conserved. Conclusion The law of conservation of momentum states, “In the absence of an external force, the momentum of a system remains unchanged.” In the elastic collision demonstrated in Table 3 the carts will collide but not stick together. Whereas in Table 1, an inelastic collision is demonstrated and the carts would proceed to stick together following collision. While momentum was not calculated for either of these options, ideally in an inelastic collision kinetic energy is not conserved, however in an elastic collision kinetic energy is conserved.