ANSWER
m = 84.375 kg
Step-by-step explanation
Given:
• The radius of the circular path, r = 27m
,
• The tangential speed of the skater, v = 12m/s
,
• The centripetal force the skater experiences, Fc = 450N
Unknown:
• The mass of the skater, m
The centripetal force an object of mass m experiences while moving through a circular path of radius r, with a tangential speed v is,

To solve for m, divide both sides by v² and multiply both sides by r,

Replace with the given values,
![m=450N\cdot(27m)/(12^2m^2/s^2)=450\operatorname{kg}\cdot m/s^2\cdot(3)/(16)s^2/m=84.375\operatorname{kg}]()
Hence, the mass of the skater is 84.375 kilograms.