Answer:
150 m
Explanation:
Distance traveled during reaction time = .5 x 30 = 15 m
Actual distance during which there was deceleration = 60 - 15 = 45 m .
force x displacement = kinetic energy
F x s = 1/2 m v² ;
F x 45 = 1/2 m 30² = 450 m ----( 1 )
for second case
Fx S = 1/2 m 50² = 1250 m --------( 2 )
Dividing( 1 )and ( 2 )
S/45 = 1250 /450 = 125 / 45
S = 125 m
Add distance traveled in reaction time in second case = 50 x .5 = 25 m
total distance required = 25 + 125 = 150 m
