A child on a spinning playground ride is 0.36 m from the center of the ride. The centripetal force on the child is 19 N. What is the mass of the child if the child has a tangential speed of 0.54 m/s?

Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path. This force is called the centripetal force which means "center seeking" force. The force has the magnitude

F = mv^2 / r

Where f is the centripetal force

M is the mass

V is the velocity

R is the radius

19 N = m (0.54 m/s) ^2 / 0.36 m

Solving for m

M = 23.5 kg