Question

A car is travelling on a straight level road with the speed 54km/h it is followed by another car b which is moving with speed of 72km/h when the distance between them is5km,the driver of car b accelerat es his car at the rate of40km/h^2after what distance and time will car b Just catch up car a

Answer 1

Answer:

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