Answer:[tex]6.72 m/s^2[/tex]
Explanation:
Given
initial velocity [tex]u=50 mi/hr\approx 73.33 ft/s[/tex]
Distance traveled before stopping [tex]s=400 ft[/tex]
using equation of
[tex]v^2-u^2=2as [/tex]
where v=final velocity
u=initial Velocity
a=acceleration
s=displacement
v=0 as car stops after travelling [tex]400 ft[/tex]
[tex]0-73.33^2=2\times a\times 400[/tex]
[tex]a=-6.72 m/s^2[/tex]
negative sign indicates it is deceleration
