Problem 8-61 Cons. of Momentum - Part 7 - A

A space vehicle and its fuel tank are moving with a velocity of \(350\; m/s\) toward a space station. The fuel tank is then jettisoned to the rear so that its velocity is only \(250\; m/s\) toward the station. What is the new speed of the space vehicle? The mass of the vehicle is \(3.25\) times that of the tank. [Ans. \(380\; m/s\)]


Accumulated Solution

Diagram A

Solution Before After
(B) \((m_1 + m_2)v\) \(m_1\; v_{1}{'} + m_2\; v_{2}{ }'\)

 


Correct!

The explosion (or whatever is used) to separate \(m_1\) and \(m_2\) exerts only internal forces on the system.

Therefore momentum is conserved.
\((m_1 + m_2)v = m_1v_1{'} + m_2 \;v_2{ '}\)

Substitute the numerical values for \(m_2\), \(v\), and \(v_1{'}\) and solve for \(v_2{ '}\)  before continuing.

Continue.