Answer:
The speed of the plane after it decelerates is 50 m/s
Explanation:
Motion with Constant Acceleration
When an object gains or losses velocity in time, it acquires acceleration. If this value is constant, we can calculate the final velocity (or speed in scalar terms) as:
[tex]v_f=v_o+at[/tex]
Where vf is the final speed, vo is the initial speed, a is the constant acceleration, and t is the time the acceleration is acting.
The plane is originally traveling at vo=80 m/s and it slows down at a constant rate of [tex]a=-0.25\ m/s^2[/tex] during t=120 seconds. Note we have added the negative sign to the acceleration because the plane is slowing down, i.e., the acceleration is against the speed.
Thus, the final speed is:
[tex]v_f=80-0.25*120[/tex]
[tex]v_f=80-30=50[/tex]
[tex]v_f = 50\ m/s[/tex]
The speed of the plane after it decelerates is 50 m/s
