A truck with mass $500\,\text{kg}$ starts from rest at the top of a stretch of track that is $400\,\text{m}$ long and $30\,\text{m}$ high, as shown. A frictional force of $250\,\text{N}$ acts on the truck for the whole journey. What is the final speed of the truck?
- A$14\,\text{m s}^{-1}$
- B$24\,\text{m s}^{-1}$
- C$31\,\text{m s}^{-1}$
- D$190\,\text{m s}^{-1}$