Final answer:
The kinetic energy of the spring toy immediately after popping should be equal to the potential energy stored in the spring right before release, which is 0.72 J. However, none of the provided options match this value, and without additional information, we cannot accurately determine which of the given options is correct.
Step-by-step explanation:
In the given scenario, the kinetic energy of the spring toy immediately after popping can be found by considering the potential energy stored in the spring just before release. In an ideal case without friction, the potential energy stored in the spring is entirely converted into kinetic energy of the toy. From the provided information, when the spring's displacement is 6 cm, the potential energy (U) is 0.72 J. Therefore, if there are no other energy losses, the kinetic energy of the spring toy immediately after popping would also be 0.72 J. However, this value is not presented in the given options. If there were energy losses, the actual kinetic energy would be lower than 0.72 J but without additional information, it's not possible to determine the exact answer from the options provided (0.068 J, 0.34 J, 0.124 J, 1.24 J).