Question

Two ice skaters initially at rest, push of each other. If one skater whose mass is $60kg$ has a velocity of $2m/s$. What is the velocity of other skater whose mass is $40kg$?

Answer 1

Given,

Initial velocity, $u_1=0and{u}_2=0$

Mass,$m_1=60kgand{m}_2=40kg$

Final Velocity, $v_1=2m{s}^{-1}$

From conservation of momentum

Final momentum = initial momentum

$m_1{v}_1+m_2{v}_2=m_1{u}_1+m_2{u}_2$

$60\times 2+40v_2=0$

$v_2=-3m{s}^{-1}$

Hence, velocity of second skater is $-3m{s}^{-1}$