Two cars A and B are traveling in the same direction with velocities v1 and v2 (v1 > v2) When the car A is at a distance d ahead of the car B, the driver of the car A applied the brake producing a uniform retardation a. There will be no collision when
Velocities are v1andv2
Car A is ahead of car B by distance d.
Step 2,
We can write
Initial relativity velocity =v1−v2,
Final relativity velocity =0
From equation of motion
v2=u2 - 2as ⇒ 0=(v1−v2)2 −2×a×s
After solving
⇒ s=(v1−v2)22a
Now we can say that
If the distance betwee two cars is 's' then collision will take place.To avoid collision
d>s ∴d> (v1−v2)22a
where d= actual initial distance between two cars.