A Rocket Is Moving in Outer Space Where No External

question 34

Multiple Choice

A rocket is moving in outer space where no external forces exist.Suppose its mass is m_R and its velocity is v_R at a particular time.When a mass m_F of fuel is ejected,the mass of the rocket becomes (m_R - m_F) and its velocity increases to (v_R+ v_R) .Suppose the fuel is always ejected at a constant speed v_F with respect to the rocket.Derive an expression for v_R as a function of m_R given the rocket's initial mass and speed are m₀ and v₀,respectively.

• A)v_R = v₀ + v_F ln(m_R/m₀)
• B)v_R = v₀ - v_F ln(m_R/m₀)
• C)v_R = v₀ - v_F exp(m₀/m_R)
• D)v_R = v₀ - v_F ln(m₀/m_R )
• E)v_R = v₀ + v_F exp(m_R/m₀)

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An economic theory that compares different countries' currencies through a "basket of goods" to assess the relative value of currencies.

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