Alight-rail commuter train accelerates at a rate of 1.35 m/s2. how long does it take to reach its top speed of 80.0 km/h, starting from rest? the same train ordinarily decelerates at a rate of 1.65 m/s2. how long does it take to come to a stop from its top speed? 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 m/s2?

16.46 seconds.

13.46 seconds

2.67 m/s²

Explanation:

Acceleration = a = 1.35 m/s²

Final velocity = v = 80 km/h =

Initial velocity = u = 0

Equation of motion

Time taken to accelerate to top speed is 16.46 seconds.

Acceleration = a = -1.65 m/s²

Initial velocity = u = 80 km/h=

Final velocity = v = 0

Time taken to stop the train from top speed is 13.46 seconds

Initial velocity = u = 80 km/h=

Time taken = t = 8.3 s

Final velocity = v = 0

Emergency deceleration is 2.67 m/s²

there are no contact forces mentioned on the list of choices that you've provided.