An athlete of mass $70\,\text{kg}$ is training by doing press-ups while carrying a load on his back. The diagram indicates the perpendicular distances concerned. The athlete’s centre of mass is $C_M$ and the centre of mass of the load he carries is $C_L$. The load has a mass of $6.0\,\text{kg}$. What upward force is exerted by his two arms?
- A$54\,\text{N}$
- B$76\,\text{N}$
- C$540\,\text{N}$
- D$760\,\text{N}$