Question

Air-track gliders with masses $300g,400g,and200g$are lined up and held in place with lightweight springs compressed between them. All three are released at once. The $200g$glider flies off to the right while the$300g$ glider goes left. Their position-versus-time graphs, as measured by motion detectors, are shown in FIGURE P11.44. What are the direction (right or left) and speed of the 400 g glider that was in the middle?

Short answer

The velocity of$400g$glider is$0.0425m/s$

Step-by-step solution

Step 1. Given information

The plot of position v/s time includes the expression for different gliders.

Step 2. Predicting the velocity

In the plot of position v/s time the slope gives the value of velocity,

Hence the velocity of glider 1 with mass $200g$is $0.53m/s$and that of glider 2 is$-0.41m/s$

Step 3. Applying the conservation principle

On the application of law of conservation of momentum we have,

$$\begin{gathered} p_i=p_f \\ {m}_1{v}_1+m_2{v}_2+m_3{v}_3=0 \\ 0.2\times 0.53+0.3\times (-0.41)+0.4\times v_3=0 \\ 0.106-0.123+0.4v_3=0 \\ 0.4v_3=0.017 \\ {v}_3=0.0425m/s \end{gathered}$$