An Australian emu is running due north in a straight line at a speed of 13.0 m/s and slows down to a speed of 10.9 m/s in 2.20 s. Assuming that the acceleration of the bird remains the same, how far the bird will travel before it comes to a full stop?

Answer 1

the deceleration is
... (13.0 -10.9) m/s / 2.20 s
... slightly less than 1 m/s^2

so it takes about 13 s to stop
... during which the average speed is
... (13.0 + 0) m/s / 2