A 5kg shell kept at rest suddenly splits up into three parts. If two parts of mas 2kg each are found flying due north and east with a velocity of `5m//s`each, what is the velocity of the third part after explosion.

Explanation

`p_x`= momentum along east =`2 kg times 5 ms^-1=10 kg ms^-1`
`p_y`= momentum along north
`=2kg times 5 ms^-1`
`=10 kg ms^-1`
resultant momentum
`p=sqrt(p_x^2+p_y^2)`
`=sqrt(10^2+10^2)`
`=10sqrt2 kg ms^-1` due north east
According to law of conservation of momentum
`p+p_3= or p_3=-p`
or `p_3=10sqrt2 kg ms^-1`
or `p_3=10sqrt2 ms^-1` due south west
`therefore v_3= 10sqrt2 ms^-1` due south west