A helicopter is ascending vertically witha speed of 5.40 m/s. At a height of 105 m above the earth a package is dropped from the helicopter.

Question

A helicopter is ascending vertically witha speed of 5.40 m/s. At a height of 105 m above the earth a package is dropped from the helicopter. How much time does is take for the package to reach the ground

in progress 0
Mít Mít 5 years 2021-07-23T14:49:04+00:00 1 Answers 95 views 0

Answers ( )

  1. ThanhThu
    0
    2021-07-23T14:50:45+00:00
    Reply

    Answer: 5.21 s

    Explanation:

    Given

    Helicopter ascends vertically with u=5.4\ m/s

    Height of helicopter h=105\ m

    When the package leaves the helicopter, it will have the same vertical velocity

    Using equation of motion

    \Rightarrow h=ut+\dfrac{1}{2}at^2\\\\\Rightarrow 105=-5.4t+0.5\times 9.8t^2\\\Rightarrow 4.9t^2-5.4t-105=0\\\\\Rightarrow t=\dfrac{5.4\pm \sqrt{5.4^2+4\times 4.9\times 105}}{2\times 4.9}\\\\\Rightarrow t=\dfrac{5.4\pm 45.68}{9.8}\\\\\Rightarrow t=5.21\ s\quad \text{Neglect negative value}

    So, package will take 5.21 s to reach the ground

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )