Asecond package is thrown downward from the plane with a vertical speed v1 = 72 m/s. what is the magnitude of the total velocity of the package at the moment it is thrown as seen by an observer on the ground? answer in units of m/s.

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

1.)the isotope cobalt-60 has a nuclear mass of 59.933820 u calculate the mass defect of cobalt-60 using the following information. mass of proton: 1.007825 u mass of neutron: 1.008665 u 1 u = 931.5 mev 2.)the isotope cobalt-60 has a nuclear mass of 59.933820 u calculate the binding energy of cobalt-60 using the following information. mass of proton: 1.007825 u mass of neutron: 1.008665 u 1 u = 931.5 mev 3.)the isotope cobalt-60 has a nuclear mass of 59.933820 u calculate the binding energy per nucleon of cobalt-60 using the following information. mass of proton: 1.007825 u mass of neutron: 1.008665 u 1 u = 931.5 mev

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.