How Are nuclear fission and nuclear fusion similar? A. Both processes are used to produce electrical power.
B. Both processes occur in stars.
C. Both processes combine smaller nuclei into larger nuclei
D. Both processes convert mass into energy.

Could someone . i have tried to solve myself but my calculation is off

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight