MHT CET202015 Oct 2020Evening ShiftPhysicsMotion in One DimensionActual
A vehicle moving with 15 ~km / hr comes to rest by covering 5 ~m distance by applying brakes. If the same vehicle moves at 45 ~km / hr , then by applying brakes, it will come to rest by covering a distance
Options
- A15 ~m
- B45 ~m
- C60 ~m
- D30 ~m .
Correct answer
B. 45 ~m
Step-by-step solution
( u =15 ~km / hr = 15 1000 60 60 = 150 36 ~m / s ) ( v ²= u ²-2 as ) ( a u² 2 ~s = 150 150 36 36 2 5 ~m / s ² ) Next ( s = u² 2 a = 45000 60 60 45000 60 60 1 2 36 36 150 15 ) (=45 ~m )