A skateboarder and her skateboard have a combined mass of $70\,\text{kg}$. By pushing against the ground with her foot, she produces a forward force $F$ of $25\,\text{N}$ on herself and the skateboard, as shown in the diagram. Before the skateboarder raises her foot away from the ground, the skateboarder and skateboard move forwards by $0.50\,\text{m}$. What is the work done by $F$ on the skateboarder and skateboard?
- A$13\,\text{J}$
- B$50\,\text{J}$
- C$340\,\text{J}$
- D$360\,\text{J}$