Answer:
[tex]5ft/s^2[/tex]
Explanation:
We will use the formula for accelerated motion [tex]v_f^2=v_i^2+2ad[/tex], which for acceleration it means:
[tex]a=\frac{v_f^2-v_i^2}{2d}[/tex]
In our case our initial velocity is [tex]v_i=100ft/s[/tex] and our final velocity is [tex]v_f=0ft/s[/tex] since it comes to rest, this process while traveling a distance [tex]d=1000ft[/tex], so we have:
[tex]a=\frac{v_f^2-v_i^2}{2d}=\frac{(0m/s)^2-(100ft/s)^2}{2(1000ft)}=-5ft/s^2[/tex]
Which in absolute value means a deceleration of [tex]5ft/s^2[/tex]