Ask Question
16 January, 08:14

A train 483 m long is moving on a straight track with a speed of 42.4 m/s. The engineer applies the brakes at a crossing, and later the last car passes the crossing with a speed of 8.6 m/s. Assuming constant acceleration, determine how long the train blocked the crossing. Disregard the width of the crossing. Answer in units of s.

+5
Answers (1)
  1. 16 January, 10:17
    0
    18.9 seconds

    Explanation:

    For the last car, we're given the information:

    x₀ = 0 m

    x = 483 m

    v₀ = 42.4 m/s

    v = 8.6 m/s

    We need to find the time, t.

    First, we find the acceleration.

    v² = v₀² + 2a (x - x₀)

    (8.6) ² = (42.4) ² + 2a (483 - 0)

    a = - 1.784

    Now, we find the time:

    v = at + v₀

    8.6 = (-1.784) t + 42.4

    t = 18.9

    The train blocks the crossing for 18.9 seconds.
Know the Answer?
Not Sure About the Answer?
Get an answer to your question ✅ “A train 483 m long is moving on a straight track with a speed of 42.4 m/s. The engineer applies the brakes at a crossing, and later the ...” in 📙 Physics if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers