Question

What does $9.8\mathrm{N}/\mathrm{kg}$ mean?

Answer 1

1. According to Newton's second law of motion, force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.
2. The mathematical relation of Newton's second law of motion:
   $$\begin{gathered} \mathrm{Force}=\mathrm{mass}\times \mathrm{acceletration} \\ \mathrm{acceleration}=\frac{\mathrm{Force}}{\mathrm{mass}} \end{gathered}$$
3. Force per mass means Newton per kg.
4. On earth, the acceleration due to gravity is $9.8\mathrm{m}/{\mathrm{s}}^2$.
5. $9.8\mathrm{N}/\mathrm{kg}$ means $9.8\mathrm{N}$ earth's gravitational field strength is required to pull $1\mathrm{kg}$ mass towards the earth's center.