physics question?

Question

A frustrated physics student blew up her Physics textbook using a small amount of explosive. It broke into three pieces, which miraculously flew off in directions that were all in the same plane. A 0.200 kg piece flew off at 20.0 m/s and a 0.100 kg piece went off at 90° to the first piece, at 30.0 m/s.

a) What was the momentum of the third piece?

b) If the mass of the third piece was 0.150 kg, what was its velocity right after the explosion?

Answer 1

Hope this helps, anybody free to correct me if I misspoke at any point. Thanks for your time.