Answer:
The total kinetic energy (EK) of the person and the skateboard can be calculated as follows:
First, calculate the kinetic energy of the person:
EK_person = (1/2) * m_person * v^2
where m_person is the mass of the person and v is the velocity of the person.
EK_person = (1/2) * 50 kg * (16 m/s)^2
EK_person = 6400 J
Next, calculate the kinetic energy of the skateboard:
EK_skateboard = (1/2) * m_skateboard * v^2
where m_skateboard is the mass of the skateboard and v is the velocity of the skateboard.
EK_skateboard = (1/2) * 5 kg * (16 m/s)^2
EK_skateboard = 640 J
Finally, add the two kinetic energies together to get the total kinetic energy:
Total EK = EK_person + EK_skateboard
Total EK = 6400 J + 640 J
Total EK = 7040 J
Therefore, the total kinetic energy of the person and the skateboard is 7040 Joules.