The system is at rest with the spring unstretched when θ = 0. The 3-kg particle is then...

The system is at rest with the spring unstretched when θ = 0. The 3-kg particle is then given a slight nudge to the right. (a) If the system comes to momentary rest at θ = 40°, determine the spring constant k. (b) For the value k = 100 N/m, find the speed of the particle when θ = 25°. Use the value b = 0.40 m throughout and neglect friction.