Calcular la masa de un cuerpo que, estando en reposo, se le aplica una fuerza de 150 N durante 30 seg, permitiéndole recorrer 10 m. ¿Qué rap

Question

Calcular la masa de un cuerpo que, estando en reposo, se le aplica una fuerza de 150 N durante 30 seg, permitiéndole recorrer 10 m. ¿Qué rapidez tendrá al cabo de ese tiempo?​

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bonexptip 4 years 2021-08-02T08:23:29+00:00 1 Answers 127 views 0

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  1. thuhuong
    0
    2021-08-02T08:24:36+00:00
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    Answer:

      v = 0.667 m / s,   m = 6746 kg

    Explanation:

    For this exercise we must use the relationship between work and kinetic energy

              W = ΔK

             

     the work is defined by

              W = F. x

     

    bold indicates vectors

              W = F x cos θ

    in this case the force is in the same direction of displacement

              W = F x    

             F x = K_f – K₀

    as the body starts from rest the initial kinetic energy is zero

             F x = ½ m v²

             

    Now let’s use the relationship between momentum and momentum

            I = Δp

            I = F t

            Δp = m v_f – m v₀

    as part of rest v₀ = 0

            F t = m v

    Let’s write our system of equations

             F x = ½ m v²

             F t = m v

    we have a system of two equations with two unknowns, let’s divide the two expressions

             x / t = ½ v

             v = 2x / t

             v = 2 10/30

             v = 0.667 m / s

    we look for the mass

             F t = m v

             m = F t / v

             m = 150 30 / 0.667

             m = 6746 kg

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