Question

Two ice skaters A and B approach each other at right angles. Skater A had a mass 30 kg and velocity 1m/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

Answer 1

Hello dear,

● Answer- 1 m/s

● Solution-
# Given-
m1 = 30 kg
u1 = 1 m/s
m2 = 20 kg
u2 = 2 m/s

# Solution-
By law of conservation of momentum,
Initial momentum = Final momentum

As skaters collide at rught angles, linear momentum is-
p = √(p1^2 + p2^2)
p = √[(m1u1)^2 + (m2u2)^2]
p = √[(30×1)^2 + (20×2)^2]
p = √(30^2 + 40^2)
p = √2500
p = 50 kgm/s

Also, momentum is given by
p = (m1 + m2) v
v = p / (m1 + m2)
v = 50 / (30 + 20)
v = 1 m/s

Final velocity of skaters is 1 m/s.

Hope this is useful...

Answer 2

Answer:1m/s

Explanation:

Acc. To conservation of momentum

M1u1+M2u2=MV. (As masses get stick together,their velocity will be same)

30i+40j=50V

30i/50+40j/50=V

3i/5+4j/5=V

V=[(3/5)^2+(4÷5)^2]^1/2

Solving this..we get,

V=1m/s