a body starts from rest and moving under uniform acceleration of 4 metre per second square travel half of its total path during last second

Question

a body starts from rest and moving under uniform acceleration of 4 metre per second square travel half of its total path during last second of its motion find the time and total distance ​

in progress 0
Euphemia 3 years 2021-08-26T08:47:39+00:00 1 Answers 13 views 0

Answers ( )

  1. Ladonna
    0
    2021-08-26T08:48:40+00:00
    Reply

    Answer:

    t = 3.414 s

    s = 23.3 m

    Explanation:

    Let t be the total time of motion

    Let s be the total distance of motion

    s – s/2 = ½at² – ½a(t – 1²) = ½a(t² – (t – 1)²)

    s/2 = ½a(t² – (t² – 2t + 1)) = ½a(t² – t² + 2t – 1)

    s = a(2t – 1)

    s = 4(2t – 1)

    s = 8t – 4

    8t – 4 = ½4t²

    8t – 4 = 2t²

    0 = 2t² – 8t + 4

    0 = t² – 4t + 2

    t = (4 ±√(4² – 4(1)(2))) / 2 = (4 ± √8)/2 = 2 ± √2

    t = 3.414 s

    or

    t = 0.5857… s which we ignore because it does not have a full last second.

    s = ½(4)3.414² = 23.3137… 23.3 m

Leave an answer

Browse

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