Physics

Question

A man is sitting on a chair with wheels. He grabs a 2.1 kg book from the desk and throws
the book at a speed of 7.2 m/s. His chair moves backward. The man has a mass of 70 kg and
the chair has a mass of 9.2 kg. What is the speed of the man and the chair after the book is
thrown?

1 Answer

  • The speed of the man and the chair after the book is thrown is 0.2 m/s.

    The given parameters:

    • mass of the book, m₁ = 2.1 kg
    • speed of the book, u₁ = 7.2 m/s
    • mass of the man, M = 70 kg
    • mass of the book, m = 9.2 kg

    The total mass of the man and the book is calculated as follows;

    m₂ = 70 kg + 9.2 kg

    m₂ = 79.2 kg

    The speed of the man and the chair after the book is thrown is determined by applying the principle of conservation of linear momentum;

    [tex]m_1 u_1 = m_2u_2\\\\u_2 = \frac{m_1u_1}{m_2} \\\\u_2 = \frac{2.1 \times 7.2}{79.2} \\\\u_2 = 0.2 \ m/s[/tex]

    Thus, the speed of the man and the chair after the book is thrown is 0.2 m/s.

    Learn more about conservation of linear momentum here: https://brainly.com/question/7538238

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