A block at rest explodes into three equal parts. Two parts starts moving along X and Y axes respectively with equal speeds of 10 m/s. Find the initial velocity of the third part.

Explanation

Let total mass = 3 m,
initial linear momentum `=3m xx 0`
Let velocity of third part `=vecV`
Using conservation of linear momentum :
`m xx 10 hati + m xx 10 hatj+m vecV=0`
So, `vecV=(-10 hati-10hatj)m//sec.`
`|vecV|=sqrt((10)^(2)+(10)^(2))=10sqrt(2)`,
making angle `135^(@)` below x-axis