Post a New Question

Physics

posted by .

A Boeing 747 "Jumbo Jet" has a length of 59.7m. The runway on which the plane lands intersects another runway. The width of the intersection is 25.0m. The plane decelerates through the intersection at a rate of 5.7 m/s(squared) and clears it with a final speed of 45.0 m/s. How much time is needed for the plane to clear the intersection?

  • Physics -

    d(tot) = 25 + 59.7 = 84.7m.

    Vf^2 = Vo^2 + 2*(-5.7)84.7 = (45)^2,
    Vo^2 - 965.58 = 2025,
    Vo^2 = 2025 + 965.58 = 2990.58,
    Vo = 54.7m/s.

    Vf = Vo + at,
    Vf = 54.7 - 5.7t = 45,
    54.7 - 5.7t = 45,
    -5.7t = 45-54.7 = -9.7,
    t = -9.7 / -5.7 = 1.70s.

  • Physics -

    1.7 seconds

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question