Question

Answer both parts below:

1A)An atomic nucleus with a rest mass energy of 7,610 MeV is accelerated to 99.325% the speed of light relative to the lab frame. What is the Kinetic Energy in MeV of the atomic nucleus in the lab frame?

I got 65,610 but got it wrong

1B) A hostile alien rocket ship is traveling at 77.1% of the speed of light towards Earth when it opens fire with a "space cannon" that shoots projectiles towards Earth. The projectiles move with a speed of 37.4% of the speed of light relative to the rocket ship. How fast are those projectiles moving relative to an observer on Earth?

I got .867 and it was wrong.

Answer 1