Those are not really compatible units; newtons is a unit of force, kilogram is a unit of mass.
Assuming normal Earth gravity, you can divide the weight in newtons by 9.8 to obtain the corresponding mass in kilograms.
100,000 kg = 980,700 newtons
25.9 kg = about 254 newtons.
7840 newtons
5.9 kg weighs 57.82 newtons (on earth, rounded), regardless of what those kg are composed of.
On Earth, 6 kg of mass weighs 58.84 newtons. (rounded)
74 pounds = about 329.2 newtons.
100,000 kg = 980,700 newtons
25.9 kg = about 254 newtons.
7840 newtons
Newtons are a measure of force, kg*m/s2
74 kg of mass weighs 120.1 newtons (27 pounds) on the moon, and the same 74 kg weighs 726 newtons (163 pounds) on Earth.
On Venus, the acceleration due to gravity is about 8.87 m/s^2. Since weight (in newtons) is equal to mass (in kg) multiplied by acceleration due to gravity, the weight of 1 kg on Venus would be 8.87 newtons.
5.9 kg weighs 57.82 newtons (on earth, rounded), regardless of what those kg are composed of.
On earth, 3 kg weighs 29.4 newtons. On the moon, the same 3 kg weighs 4.8 newtons. On the way there and back, the same 3 kg weighs zero newtons.
81 newtons.
81 newtons.
81 newtons.