physics
posted by Swag .
An automobile and train move together along
parallel paths at 39.1 m/s.
The automobile then undergoes a uniform
acceleration of −4 m/s
2
because of a red lightand comes to rest. It remains at rest for 22.5 s,
then accelerates back to a speed of 39.1 m/s
at a rate of 2.53 m/s
2
.
How far behind the train is the automobile
when it reaches the speed of 39.1 m/s, assuming that the train speed has remained at
39.1 m/s?
Answer in units of m

physics 
bobpursley
times involved:
deacceleratin: 39.1/4 seconds
sittn still: 22 seconds
accelerating: 38.1/2.53 seconds
distance traveled: time deacc*39.1/2 + timeaccelerating*39.1/2
avg velocity= distance traveled/total time.
distance behind train: avgvelocitydifference*timetotalelapsed
=(39.1avgvelocity)*totaltimeelpased.
Respond to this Question
Similar Questions

Physics (12)
A car and train move together along parallel paths at 25 m/s [W]. The car then undergoes a uniform acceleration of 2.5m/s^2 [E] because of a red light and comes to rest. It remains at rest for 45s, then accelerates back to a velocity … 
physics help
A 1100 kg automobile is at rest at a traffic signal. At the instant the light turns green, the automobile starts to move with a constant acceleration of 3.0 m/s2. At the same instant a 2800 kg truck, traveling at a constant speed of … 
Physics
An automobile and train move together along parallel paths at 31.6 m/s. The automobile then undergoes a uniform acceleration of −4 m/s2 because of a red light and comes to rest. It remains at rest for 44 s, then accelerates back … 
Physics
An automobile accelerates from rest at 1.3 m/s 2 for 19 s. The speed is then held constant for 23 s, after which there is an acceleration of −0.9 m/s 2 until the automobile stops. What total distance was traveled? 
Honors Physics
An automobile accelerates from rest at 1.3 m/s 2 for 19 s. The speed is then held constant for 23 s, after which there is an acceleration of −0.9 m/s 2 until the automobile stops. What total distance was traveled? 
Physics
An automobile and train move together along parallel paths at 21.8 m/s. The automobile then undergoes a uniform acceleration of −4 m/s 2 because of a red light and comes to rest. It remains at rest for 19.1 s, then accelerates … 
physics
An automobile and train move together along parallel paths at 20.3 m/s. The automobile then undergoes a uniform acceleration of −4 m/s2 because of a red light and comes to rest. It remains at rest for 19.4 s, then accelerates … 
physics
An automobile and train move together along parallel paths at 28.8 m/s. The automobile then undergoes a uniform acceleration of −4 m/s 2 because of a red light and comes to rest. It remains at rest for 63.8 s, then accelerates … 
physics
A light–rail commuter train draws 645 A of 590–V DC electricity when accelerating. What is its power consumption rate in kilowatts? 
Physics
An automobile and a truck start from rest at the same instant, with the automobile initially at some distance behind the truck. The truck has a constant acceleration of 2.15m/s2 , and the automobile an acceleration of 3.47m/s2 . The …