An airplane starts from rest and moves forward with a constant acceleration of 5 m/s2 along a runaway 250 m long. How long does it take the plane to reach a speed of 46.0 m/s?

v = a t

5 t = 46

To find the time it takes for the airplane to reach a speed of 46.0 m/s, we can use the following kinematic equation:

v = u + at

Where:
v = final velocity (46.0 m/s)
u = initial velocity (0 m/s since the plane starts from rest)
a = acceleration (5 m/s²)
t = time

Rearranging the equation to solve for time (t), we get:

t = (v - u) / a

Substituting the given values into the equation, we have:

t = (46.0 m/s - 0 m/s) / 5 m/s²

t = 46.0 m/s / 5 m/s²

t = 9.2 s

Therefore, it will take the plane 9.2 seconds to reach a speed of 46.0 m/s.