Question

Two skaters A and B of mass 50 kg and 70 kg respectively stand facing each other 6 m apart. Then they pull a rope stretched between them. How far has each moved when they meet?

• A. A moves 3.5 m and B 2.5m
• B. A moves 2 m and B 4m
• C. both have moved 3 m
• D. both have moved 2.5 m

Answer 1

The correct option is A A moves 3.5 m and B 2.5m

Since force applied on both the should be equal and opposite,
$\therefore m_1{a}_1=m_2{a}_2$
i.e. $m_1{s}_1=m_2{s}_2$
Also,
$s_1+s_2=6$
$\therefore 50\times s_1=70\times s_2$
$\therefore 50\times s_1=70\times (6-s_2)$
$\therefore s_1=3.5$ m