Answer:
100 seconds
Erica and Amy are at distance of 1 km in 100 seconds
Step-by-step explanation:
They both are travelling in opposite directions so the sum of the distances they travel is the distance between them.
Let's take t as the total time taken to achieve a seperation of 1km
Distance traveled by Erica , (Speed of Erica - v1)
x1 = v1 * t
Distance travelled by Amy , (Speed of Amy - v2)
x2 = v2*t
Therefore sum of the distances they traveled is x1+x2 = x
x = v1*t + v2*t
x = t*(v1 + v2)
Here it is given that final seperation between Amy and Erica is 1km or 1000 m
Therefore x = 1000 m
Thus t = [tex]\frac{x}{v1+v2}[/tex]
Substituting given values v1 = 6 m/s v2 = 4 m/s
Therefore,
They are apart by exactly 1km in a time of 100 sec
