Answer:
Step-by-step explanation:
If F be the force acting on the car to stop it
work done by force = change in kinetic energy
F X 80 = 1/2 m x 20²
F = 2.5 m
If speed is 10m/s
for distance d , the equation is
F x d = 1/2 x m x 10²
2.5 m x d = 1/2 x m x 10²
d = 20 m
If velocity is 40 m /s
F x d = 1/2 x m x 40²
2.5m x d = 1/2 m x 1600
d = 320 m
For v = 5 m/s
F x d = 1/2 m x 5²
2.5 m x d = 1/2 m x 5²
d = 5 m .