A-B) 26.8 s
The plane accelerates at a rate of
And the total distance covered by the plane is the length of the runaway
d = 1800 m
The plane starts from rest, so its initial velocity is
u = 0 m/s
We can solve this part of the problem by using the following SUVAT equation:
where
t is the time the plane needs to cover the distance d.
Since u = 0, the equation can be rewritten as
So we can now solve for t:
C) 2.50 m
We now want to calculate the distance travelled by the plane in the first second of its motion: therefore, we just need to use
t = 1 s
And use again the same equation
Again, since u = 0 at the beginning of the motion,
So by substituting t = 1 we find
D) 132 m
This part is a bit different, since first we have to find the velocity of the plane when the last second starts.
As we found in part A-B, the total time of the motion is 26.8 s. So we need to find the velocity of the plane when the last second starts, which means at
The velocity is given by
where
u = 0
a = 5.00 m/s^2
t' = 25.8 s
Substituting,
Now we can use the following SUVAT equation:
where
to find the distance covered by the plane in the last second. Substituting,