In: Physics
An explosion aboard a stationary spacecraft breaks it into 3 well-defined and identifiable pieces. From a space station you capture a video of the explosion. A 2500-kg piece flies off at 200 m/s in the –x-direction (as seen on the video monitor), a 1500-kg piece moves away at 220 m/s at an angle of 34° above the +x axis. The third piece you know to be 1800 kg but its path cannot be seen on the video. You want to know which way it’s headed in case it moves toward another space station. What is the velocity of this third fragment? Assume all the pieces lie in the same (xy) plane.
The situation can be visualized as
Initially, when there is no explosion, the initial momentum of the system is zero.
Now, after the explosion, the momentum of the system is
The conservation of momentum gives us
That gives us
and
Now, from the above calculation
We have
So, the velocity of the third mass is 162.3 m/s in the direction 39.2o below the positive x-axis(as shown in the figure).