I think metal, steel and copper.
Helium has an atomic mass of 4.00 atomic mass units.
I believe the correct answer is C all the other options seem funny to me
If the award weighs 200 newtons and 200 newtons equals 44.96 pounds of force even though it is of such a force if it hits the ground the energy will either discharge into the air doing nothing but creating a loud sound or it will discharge into the ground altering the ground that it landed on.
Hope this helps :)
Work formula:
W = F * d
F 1 = 40 N, d 1 = 6 m;
F 2 = 30 N; d 2 = 6 m.
W ( Cindy ) = 40 * 6 = 240 Nm
W ( Andy ) = 30 * 6 = 180 Nm
The difference of their amounts if work:
240 Nm - 180 Nm = 60 nm
hope it helps!