The motion of a particle in the XY plane is given by x(t)=25+6t2 m x(t) = 25 + 6t^2 \, \text{m} x(t)=25+6t2m; y(t)=−50−20t+8t2 m y(t) = -50 - 20t + 8t^2 \, \text{m} y(t)=−50−20t+8t2m. The magnitude of the initial velocity of the particle, v0 v_0 v0, is given by: