A block with mass $2.0\,\text{kg}$ is let go from rest on an incline. It moves $7.0\,\text{m}$ along the slope and descends through a vertical height of $3.0\,\text{m}$. A frictional force of $5.0\,\text{N}$ acts parallel to the slope on the block. What is the block’s speed after it has fallen this distance?
- A$4.9\,\text{m s}^{-1}$
- B$6.6\,\text{m s}^{-1}$
- C$8.6\,\text{m s}^{-1}$
- D$10\,\text{m s}^{-1}$