oscillating spring mass systems can be used to experimentally determine an unknown mass without using a mass balance. a student observes that a particular spring-mass system has a frequency of oscillation of 10 Hz. the spring constant of the spring is 250 N/m. what is the mass?

Is this correct
F=1/2pisqrt(k/m)
10=1/2pisqrt((250))/m
M= 0.063326 kg

Yes, mass is correct

please be careful with parentheses
F= (1/2pi) sqrt(k/m)
10=( 1/2pi ) sqrt ( 250 / m)