Answer:
The distance between the person and the balloon after 2 seconds the person starts walking is changing on 4.47 m/s
Explanation:
The relative position between the balloon and the person is found using Galileo's relativity principle:
(1)
with Rb the position of the balloon and Rp the position of the person respect with the origin (See Figure 1). Because we don’t have those positions but we know the constant velocities, we can relate the positions (R) with the velocities (v) with the kinematic equation:
(2)
So equation (1) is:
(3)
with and
the unitary vectors on y and x direction respectively.
We see from our initial condition (See figure 2) that:
(4)
So if we put this on (3) and divide by time we have:
(5)
But we are interested in how fast a distance is changing, and that is a speed so:
