Answer:
0.2 m
Explanation:
PHASE 1
First, we calculate the distance the tongue moved in the first 20 ms (0.02 secs). We use one of Newton's equations of linear motion:
[tex]s = ut + \frac{1}{2}at^2[/tex]
where u = initial velocity = 0 m/s
a = acceleration = [tex]250 m/s^2[/tex]
t = time = 0.02 s
Therefore:
[tex]s = 0 + \frac{1}{2} * 250 * (0.02)^2\\\\\\s = 0.05 m[/tex]
PHASE 2
Then, for the next 30 ms (0.03 secs), we use the formula:
[tex]distance = speed * time[/tex]
This speed is the same as the final velocity of the tongue after the first 20 ms.
This can be obtained by using the formula:
[tex]v = u + at\\\\=> v = 0 + (250 * 0.02)\\\\\\v = 5 m/s[/tex]
Therefore:
distance = 5 * 0.03 = 0.15 m
Therefore, the total distance moved by the tongue in the 50 ms interval is:
0.05 + 0.15 = 0.2 m