A firecracker explodes into two pieces, the first piece has mass m, and the second piece has mass m. You may assume throughout that the mass of the explosive substance is negligible.

A) Suppose the firecracker was at rest before the explosion, and the first piece travels at speed v in the upwards (+y) direction immediately after the explosion. The explosion is so short and violent that you can ignore all other forces. What is the velocity v (magnitude and direction) of the 2nd piece immediately after the explosion? 

B) What if the firecracker was initially traveling straight up, in +y direction, with initial speed u before the explosion? Find an expression for v (the y-component of ) in terms of m, m2, V, and u. What is the critical speed u, such that the 2nd piece is instantaneously at rest after the explosion (neither going up nor down). 

C) Above, we said the explosion was so short we could ignore all other forces. But, suppose the firecracker explosion takes a finite time At, during whi