A speed-time graph for an object is shown. There are four statements below about the object's acceleration. Which statement is correct?
- AThe acceleration in the first $10\,\text{s}$ is $\frac{10}{10}\,\text{m s}^{-2}$.
- BThe acceleration increases between W and X.
- CThe acceleration decreases between Y and Z.
- DThe deceleration between Y and Z is $\frac{10}{50}\,\text{m s}^{-2}$.