PLEASE HELP An object is thrown upward with an initial velocity of 32.1 m/s. What is its velocity in 4.0 s? (use g = 9.81 m/s2). Please incl

Question

PLEASE HELP An object is thrown upward with an initial velocity of 32.1 m/s. What is its velocity in 4.0 s? (use g = 9.81 m/s2). Please include step by step process. -7.14 11.2 7.14 -4.6

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Khải Quang 4 years 2021-08-28T10:15:38+00:00 1 Answers 74 views 0

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  1. thnahdat
    0
    2021-08-28T10:16:43+00:00
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    Answer:

    -7.14

    Explanation:

    According to equation of motion

    v = u + at

    where

    v is the final velocity at any time t

    u is the initial velocity

    a is the acceleration

    and t is the time

    ___________________________________________

    Given

    An object is thrown upward it means

    its initial velocity is in upward direction

    but acceleration due to gravity is in downward direction which will cause to decrease the velocity of object.

    Intial velocity u = 31.1 m/s

    final velocity v at 4 second we have to find.

    t = 4 second

    a = g = 9.81 m/s2 (it is acting in opposite direction of motion hence its sign will be negative ).

    Thus

    a = –  9.81 m/s2

    using the above values in v = u + at

    v = 32.1 – 9.81*4

    v = 32.1 – 39.24

    v = -7.14

    Thus, correct option is -7.14.

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