A car is travelling on a straight level road with a uniform speed of 60km/h.It is followed by another car B .Which is moving with a speed of 70km/h.When the distance between them os 2.5 km the car B given a deceleration of 20km/h^2 .after how much time will b catch up with a
Answers
Answer:
probably 10 seconds.....
Answer:
For B to catch A both will have to reach the same point in same time.
Let that distance be x . B will have to cover x+2kmin the same time.
For B equation will be
x=60km/hr×t
t=
60
x
hr
For A equation will be
x+2=70km/hr×
60
x
hr+
2
1
×−20km/hr
2
×(
60
x
)
2
x
2
−60x+720=0
The solution for the above equation using the quadratic formula will be
x=30(1±
2
)km
As we have to find the shortest distance, that distance will be
x=30(1−
2
)km
Explanation:For B to catch A both will have to reach the same point in same time.
Let that distance be x . B will have to cover x+2kmin the same time.
For B equation will be
x=60km/hr×t
t=
60
x
hr
For A equation will be
x+2=70km/hr×
60
x
hr+
2
1
×−20km/hr
2
×(
60
x
)
2
x
2
−60x+720=0
The solution for the above equation using the quadratic formula will be
x=30(1±
2
)km
As we have to find the shortest distance, that distance will be
x=30(1−
2
)km