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Two Metra trains approach each other on separate but parallel tracks. Train A has a speed of 90 km/hr, and train B has a speed of 80 km/hr. Initially, the two trains are 2.71 km apart.

a. How long will it take the two trains to meet?
b. Write two complete equations that describe the position of:
Train A:
Train B:
c. At what exact time will train A and train B be at the same position?
d. At what position is train A when it meets train B?
e. How far has train B traveled in this time?

1 Answer

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Final answer:

The two trains will meet in 0.0159 hours. The position equations for Train A and Train B are x = 90t and y = 2.71 - 80t, respectively. The trains will be at the same position after approximately 0.016 hours.

Step-by-step explanation:

To find the time it will take for the two trains to meet, we can use the formula:

Time = Distance / Relative Speed

The distance between the two trains is initially given as 2.71 km. The relative speed is the sum of the speeds of the two trains, which is 90 km/hr (Train A) + 80 km/hr (Train B) = 170 km/hr.

Substituting the values into the formula, we get:

Time = 2.71 km / 170 km/hr = 0.0159 hours

To write the position equations for each train, we can assume that Train A is at position x and Train B is at position y. The positions can be written as:

Position of Train A: x = 90t

Position of Train B: y = 2.71 - 80t

To find the exact time when the two trains are at the same position, we can set the positions equal to each other:

90t = 2.71 - 80t

Solving for t, we get:

170t = 2.71

t = 2.71 / 170 = 0.016 hours

At this exact time, the positions of both trains will be the same.

To find the position of Train A when it meets Train B, we can substitute the value of t into the position equation of Train A:

x = 90 * 0.016 = 1.44 km

Finally, to find how far Train B has traveled in this time, we can substitute the value of t into the position equation of Train B:

y = 2.71 - 80 * 0.016 = 1.37 km

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