Question

Two ice skaters $A$ and $B$ approach each other at right angles. Skater $A$ has a mass $30kg$ and velocity $1m/s$ skater $B$ has a mass $20kg$ and velocity $2m/s.$ They meet and cling together. Their final velocity of the couple is:

• A. $2m/s$
• B. $1.5m/s$
• C. $1m/s$
• D. $2.5m/s$

Answer 1

The correct option is C $1m/s$

$m_1{v}_1+\left(m_2{\overrightarrow{v}}_2\right)=\left(m_1+m_2\right)v$

$\sqrt{{\left(30\times 2\right)}^2+{\left(20\times 2\right)}^2}=\left(50\right)V$

$50=50\times v$

$v=1m/s$