Final answer:
The final velocity of the airplane is computed using the kinematic equation v = vo + at. With the initial velocity vo = 70.0 m/s, a deceleration of a = -1.50 m/s² over a period of t = 40.0 s, the final velocity is found to be 10.0 m/s.
Step-by-step explanation:
To calculate the airplane's final velocity, we can use the kinematic equation v = vo + at. Here, vo is the initial velocity, a is the acceleration, and t is the time. The known values are vo = 70.0 m/s, a = -1.50 m/s² (negative because the acceleration is in the opposite direction of the velocity), and t = 40.0 s.
We substitute the known values into the equation to find the final velocity:
Identify the knowns: vo = 70.0 m/s, a = −1.50 m/s², t = 40.0 s.
Identify the unknown, which is final velocity, Uf.
Determine which equation to use: v = vo + at.
Plug in the known values and solve: v = 70.0 m/s + (−1.50 m/s²) (40.0 s) = 10.0 m/s.
Therefore, the airplane's final velocity is 10.0 m/s.