When NASA's Skylab reentered the Earth's atmosphere on July 11, 1979, it broke into a myriad of pieces. One of the largest fragments was a 1770-kg lead-lined film vault, and it landed with an estimated speed of 120 m/s.?

Kinetic Enerrgy = 12744000 J or 12.744 MJ

Explanation:

Given Data:

Mass of fragment = m =1770 kg    ;

Estimated speed = v = 120 m/sec ;

Solution:

As we know that

Kinetic energy = K.E = (1/2)mv²

By putting the values, we get

              K.E = 0.5*1770*120²

              K.E = 12744000 J

                            or

              K.E = 12.744 MJ

So, the kinetic energy of lead-lined vault when it landed was 12.744MJ approximately.