An object initially at rest explodes into three pieces,each of which has the same mass.Piece one moves north and piece two moves east.Which piece has the largest speed?
A)piece one
B)piece two
C)piece three
D)They all have the same speed.

Question

Quizplus · Accepted Answer

Since the object initially was at rest, its initial momentum was zero. To conserve momentum, the vector sum of the momenta of the three pieces must also be zero. If pieces one and two move perpendicular to each other (north and east), the third piece must move in the opposite direction to the vector sum of the first two pieces to balance the momentum. Given that all pieces have the same mass, for the momentum vectors to cancel out, the speed of the third piece must be larger than the speed of the first two pieces, as it has to counteract the combined momentum of the other two.

An Object Initially at Rest Explodes into Three Pieces,each of Which