A 17-car train standing on the siding is started
in motion by the train’s engine. 4 cm slack is
between each of the cars, which are 9 m long.
The engine is tightly connected to the first car
and moves at a constant speed of 25 cm/s.
How much time is required for the pulse to
travel the length of the train?
well, the total slack is 16*4cm = 64cm
so, as the slack is reduced by 25 cm/s, and time = distance/speed, ...
The length of each car does not matter, unless there is some stretch constant telling how long it takes for the pulse to move the length of the car.
To find out how much time is required for the pulse to travel the length of the train, we need to first calculate the total length of the train and then divide it by the speed of the pulse.
Here's how you can do it:
1. Calculate the length of each car: Each car is 9 m long, so the total length of a car including the slack is 9 m + 4 cm.
2. Calculate the total length of the train: Since there are 17 cars, we need to multiply the length of each car by the number of cars, and then add the length of the slack between each car. Thus, the total length of the train is (9 m + 4 cm) * 17.
3. Convert the length of the train to centimeters: Since the speed of the pulse is given in centimeters per second, we need to convert the total length of the train from meters to centimeters by multiplying it by 100.
4. Divide the length of the train by the speed of the pulse: Divide the total length of the train in centimeters by the speed of the pulse, which is 25 cm/s.
Let's do the calculations:
Length of each car = 9 m + 4 cm = 904 cm
Total length of the train = 904 cm * 17 = 15368 cm
Time required for the pulse to travel the length of the train = 15368 cm / 25 cm/s
Now, divide 15368 cm by 25 cm/s to find the time:
15368 cm / 25 cm/s = 614.72 seconds (rounded to two decimal places)
Therefore, it would take approximately 614.72 seconds for the pulse to travel the length of the train.