A firecracker in a coconut blows the coconut into three pieces. Two pieces of equal mass fly off south and west, perpendicular to each other, at 21m/s . The third piece has twice the mass as the other two.

Question

What is the speed of the third piece?

What is the direction of the third piece?

Answer 1

I would use conservation of momentum in the S and west direction.

S direction
M*21S+2M*v S=0

so v in the South direction is -10.5
so the same in th eEast direction
v in the East Direction

V=-10.5 E

angle= arctan 10.5/10.5 or NE at velocity 10.5*sqrt2