An aircraft lands with an initial velocity of 70.0 m/s and then decelerates at 1.50 m/s^2 for 40.0 s. What is its final velocity?

1. Identify the knowns: the initial velocity is 70.0 m/s, the acceleration is -1.50 m/s^2 and the time is 40.0 s. 2. The acceleration is negative because it points opposite to the positive velocity. 3. Use final velocity equals initial velocity plus acceleration times time. 4. Substitute the values: 70.0 m/s + (-1.50 m/s^2)(40.0 s) = 70.0 m/s - 60.0 m/s = 10.0 m/s. 5. The result stays positive, so the aircraft is still rolling forward rather than backing up. 6. Subtracting only 1.50 m/s gives 68.5 m/s and ignores the 40.0 s the braking lasted. _Source: OpenStax College Physics (CC BY 4.0), Ch 2 "Kinematics", section 2.5 Motion Equations for Constant Acceleration in One Dimension_