I cant understand how to prove this question. We learned about intermediate value theorem but this makes no sense because $120$ km isn't in bounds of either upper or lower limit. Here is the question
At $2:00$ PM, a car's speedometer reads $30$km/h. At $2:10$ PM, it reads $50$ km/h. Show that at some time between $2:00$ and $2:10$ the acceleration was exactly $120$ $\text{km}/\text{h}^2$ (YES she wrote the question are $\text{h}^2$. I hope its a typo). Indicate which theorem you must use in your explanation.