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

Question

Two ice skaters A and B approach each other at right angles. Skater A has a mass 30 kg and velocity 1 m / s and skater B has a mass 20 kg and velocity 2 m / s. They meet and cling together. The final velocity of the couple is (A) 2 m / s (B) 1.5 m / s (C) 1 m / s (D) 2.5 m / s

Tardigrade Admin · Accepted Answer

Applying principle of conservation of linear momentum, p=√p12+p22 or (m1+m2) v=√(m1 v1)2+(m2 v2)2 or (30+20) v=√(30 × 1)2+(20 × 2)2=50 ∴ v=(50/50)=1 m / s

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

2 m / s

1.5 m / s

1 m / s

2.5 m / s

Applying principle of conservation of linear momentum,
$p = p_{1}^{2} + p_{2}^{2}$
or $(m_{1} + m_{2}) v = (m_{1} v_{1})^{2} + (m_{2} v_{2})^{2}$
or $(30 + 20) v = (30 \times 1)^{2} + (20 \times 2)^{2} = 50$
$∴ v = \frac{50}{50} = 1 m / s$

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