physics
posted by bill .
please HELP!!!
What is the magnitude of the momentum of a baseball (m = 1.450 kg) traveling at a speed of 102 mi/h? Express your answer in SI units.
I am unsure where to start

convert mi/hr into meters/sec.
Check your answer here: Put in the Google search window
102 miles/hr in m/s 
P = mv
P = 1450(kg) x 102(m/s) = 147900 (kg m/s)