Answer:
Explanation:
Given
Initial speed [tex]u=60\ mi/hr\approx 88\ ft/s[/tex]
distance traveled before coming to rest [tex]d_1=120\ ft[/tex]
using equation of motion
[tex]v^2-u^2=2as [/tex]
where v=final velocity
u=initial velocity
a=acceleration
s=displacement
[tex]0-(88)^2=2\times a\times 120---1[/tex]
for [tex]u_2=80\ mi/hr\approx 117.33\ ft/s[/tex]
using same relation we get
[tex]0-(117.33)^2=2\times a\times (d_2)----2[/tex]
divide 1 and 2 we get
[tex](\frac{88}{117.33})^2=\frac{120}{d_2}[/tex]
[tex]d_2=213.32\ ft[/tex]
So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed
