Question

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 10.6 m/s in 4.0 s.. (a) What is the direction of the bird’s acceleration? (b) Assuming that. the acceleration remains the same, what is the bird’s velocity after an. additional 2.0 s has elapsed?

Answer 1

The acceleration of the bird is the quotient obtained when the difference of its final and initial velocities is divided by the time elapsed.
a = (Vf - V1) / t
a = (10.6 m/s - 13 m/s) / 4 = -0.6 m/s²
Thus, the acceleration is equal to -0.6 m/s².
For the velocity after 2 seconds,
Vf2 = Vf1 + at
Substituting,
Vf2 = 10.6 m/s + (-0.6) x 2 = 9.4 m/s