2.5 Exercise 6

(a) A light-rail commuter train accelerates at a rate of $1 . \text{35 m}/\text{s}^{2}$. How long does it take to reach its top speed of 80.0 km/h, starting from rest? (b) The same train ordinarily decelerates at a rate of $1 . \text{65 m}/\text{s}^{2}$. How long does it take to come to a stop from its top speed? (c) In emergencies the train can decelerate more rapidly, coming to rest from 80.0 km/h in 8.30 s. What is its emergency deceleration in $\text{m}/\text{s}^{2}$?