Question

How much would a 15.0 kg object weigh on Neptune?

Answer 1

the gravity on Neptune is 11.15 m/s²
the gravity on earth is 9.81 m/s²
divide the Neptune and earth gravity we get 1.13
which means object on neptune is 1.13 heavier than earth
yield, weigh of the object on neptune is 1.13×15=17.04kg

Answer 2

Weight = (mass) · (gravity)

Weight = (15.0 kg) · (11.2 m/s²)

Weight = (15.0 · 11.2) · (kg · m/s²)

Weight = 168 Newtons