# A food packet is dropped from the plane going at an altitude of 100 m. What is the path of the...

## Question:

A food packet is dropped from the plane going at an altitude of 100 m. What is the path of the packet as seen from the plane? What is the path of the packet as seen from the ground? If someone asks 'what is the actual path', what will you answer?

## Frame of reference

Motion is relative. The way we perceive motion depends on which frame of reference we are observing. This changes a lot especially if there is a difference between the speed at which each frame is travelling.

As the food packet left the plane, it has an initial velocity similar to the velocity of the plane so difference in their relative velocity is zero so the packet will just move vertically downwards. To visualize this, let's assume that the plane is travelling at constant speed horizontally (ignoring the effects of air resistance. The food packet will have the same horizontal speed throughout its flight so distance they traveled horizontally is just similar so if you view the packet it will appear to be straightly oriented with the plane making it look like its falling vertically. However as seen from the ground since the observer is stationary, there is a net difference between their relative velocity. The food packet will eventually gain a vertical component on its velocity due to gravity so its path would be parabolic as what we should expect from our kinematic equations. If someone asks the actual path, the correct answer is there is none. Each path is valid because motion is relative so it will be really dependent on the frame of reference at which it is being observed.