When two objects are moving along a straight line in the same direction, the distance between them increases by 6 m in one second. If the objects move with their constant speed towards each other the distance decreases by 8 m in one second, then the speed of the objects are :
Let the speeds of the two objects be v1 and v2. When the two objects are moving in the same direction, the relative speed is given by: |v1−v2| According to the problem, this relative speed results in an increase in the distance between them by 6 m in one second. Therefore, we have: |v1−v2|=6 When the two objects are moving towards each other, the relative speed is given by: v1+v2 In this case, the distance decreases by 8 m in one second, so we have: v1+v2=8 We now have two equations: ‌|v1−v2|=6 ‌v1+v2=8 We can solve these equations by considering the absolute value condition in two cases: Case 1: v1≥v2 v1−v2=6‌‌(. from |v−1−v−2|=6) v1+v2=8 Adding these two equations: (v1−v2)+(v1+v2)=6+8
‌2v1=14 ‌v1=7 Substituting v1=7 into v1+v2=8 : ‌7+v2=8 ‌v2=1
‌‌ Case 2: ‌v1<v2 ‌v2−v1=6‌‌(‌ from ‌|v−1−v−2|=6) ‌v1+v2=8 Adding these two equations: ‌(v2−v1)+(v1+v2)=6+8 ‌2v2=14 ‌v2=7 Substituting v2=7 into v1+v2=8 :
‌v1+7=8 ‌v1=1 From both cases, we find that the speeds of the objects are 7ms−1 and 1ms−1. Therefore, the correct answer is: Option B: 7ms−1 and 1ms−1