Final answer:
The kinetic energy of the asteroid just before it hits Earth is 64 J.
Step-by-step explanation:
The kinetic energy of the asteroid just before it hits Earth can be calculated using the formula: KE = 0.5 * mass * velocity^2. From the information given, we know the mass of the asteroid is 7.0 kg and the final velocity is 4.286 m/s. Plugging these values into the formula, we get: KE = 0.5 * 7.0 * (4.286)^2 = 64 J. Therefore, the correct answer is 64 J.
Without the specific values for the mass and velocity, we can't provide an exact answer. However, the kinetic energy will be proportional to the square of the velocity. Therefore, if the velocity is doubled, the kinetic energy will be four times greater. Similarly, if the velocity is halved, the kinetic energy will be one-fourth.
Check the provided values for velocity and mass, and use the formula to calculate the kinetic energy accordingly. The correct option would be the one that corresponds to the calculated kinetic energy.