PHYSICS question please please please help!!!!!?

Question

An automobile traveling 105 km/h overtakes a 1.50 km long train traveling in the same direction on a track parallel to the road.
1). If the train's speed is 75 km/h, how long does it take the car to pass it? in hr

2). How far will the car have traveled in this time? in km

3). What are the results if the car and train are traveling in opposite directions? in km

Please i really need to know how to do this and also please show the work Thanks :)

Answer 1

1) Divide the length of the train by the difference in speed to get hours. Then multiply by 60 to get minutes.
1.5 km / (105-75) km/h = 0.05 h = 3 min.

2) Multiply the hours in answer 1) by the car's speed to get its distance traveled.
0.05 h * 105 km/h = 5.25 km

3) Using the formula from question 1), change the train's speed to a negative number (since they're traveling in opposite directions), then proceed normally.
1.5 km / [105-(-75)] km/hr = 0.00833 h = 0.5 min = 30.0 sec.

Answer 2

The key to this kind of problem is to recognize the difference in speed.
105 - 75 = 30
Now imagine the train is not moving and the car is going 30 km/h
Also in order for your answer to be correct you need the length of the car as it does not pass the train until the back of the car is beyond the front of the train.

For the other direction add the speeds.
105 + 75 = 180 km/h
Now you may consider the train motionless and the car going 180 km/h once again you still need the length of the car.

When calculating the distance the car traveled remember to use the actual speed of the car times the time you arrived at using the
difference speed and summed speed.

I did the simplification you do the math.