Answer :

olemakpadu
F  =  ma.         

Note Force should  be = 150 N.  Acceleration = 30 m/s2   ( Am presuming for your question you meant to write 30m/s2  and not 30m/s as you wrote)

150 = m ( 30)

150/30  = m.

5 = m

Mass of the object = 5 Kg.