Answer:
60 m
Explanation:
Case 1:
v₀ = initial speed = 25 mph = 11.2 m/s
v = final speed = 0 m/s
a = acceleration = ?
d = stopping distance = 15 m
using the kinematics equation
v² = v₀² + 2 a d
0² = 11.2² + 2 a (15)
a = - 4.2 m/s²
Case 2 :
v₀ = initial speed = 50 mph = 22.4 m/s
v = final speed = 0 m/s
a = acceleration = - 4.2 m/s²
d = stopping distance = ?
using the kinematics equation
v² = v₀² + 2 a d
0² = 22.4² + 2 (- 4.2) d
d = 60 m
