An Australian emu is running due south in a straight line at a speed of 16.9 m/s and slows down to a speed of 13.9 m/s in 3.5 s.

Assuming that the acceleration remains the same, what is the bird's velocity after an additional 2.0 s has elapsed? (Assume that due south is the positive direction. Indicate the direction with the sign of your answer.)

a=(V-Vo)/t=(13.9-16.90)/3.5=-0.769m/s^2

V = Vo _ a*t
V = 13.9- 0.769*2 = 12.4 m/s.

To find the bird's velocity after an additional 2.0 seconds has elapsed, we can use the equation of motion:

v = u + at

Where:
v = final velocity
u = initial velocity
a = acceleration
t = time

Given that the emu slows down from 16.9 m/s to 13.9 m/s in 3.5 seconds, we can calculate the acceleration:

a = (v - u) / t
a = (13.9 m/s - 16.9 m/s) / 3.5 s
a = -3 m/s^2

Since velocity is a vector quantity and the emu is moving due south, we'll use negative sign to denote the direction opposite to the positive (north) direction.

Now, let's find the final velocity after an additional 2 seconds:

t = 2.0 s
u = 13.9 m/s
a = -3 m/s^2

v = u + at
v = 13.9 m/s + (-3 m/s^2) * 2.0 s
v = 13.9 m/s - 6 m/s
v = 7.9 m/s

Therefore, the bird's velocity after an additional 2.0 seconds has elapsed is 7.9 m/s due south.

To find the bird's velocity after an additional 2.0 seconds, we can use the equation:

v = u + at

where:
v = final velocity
u = initial velocity
a = acceleration
t = time

We are given:
initial velocity, u = 13.9 m/s
acceleration, a = (13.9 m/s - 16.9 m/s) / 3.5 s = -0.857 m/s^2 (negative because the bird is slowing down)
time, t = 2.0 s

Substituting the given values into the equation, we have:

v = 13.9 m/s + (-0.857 m/s^2) * 2.0 s
v = 13.9 m/s - 1.714 m/s
v = 12.186 m/s

Therefore, the bird's velocity after an additional 2.0 seconds is 12.186 m/s, in the negative direction, which indicates it is moving in the opposite direction, i.e., due north.