[Mentor's note: Thread title changed to reflect question content] I really need some help with this one: 1. The problem statement, all variables and given/known data An unhappy rodent of mass 0.307kg , moving on the end of a spring with force constant 2.48N/m , is acted on by a damping force Fx=−b⋅vx. Part A If the constant b has the value 0.894kg/s , what is the frequency of oscillation of the mouse? Part B For what value of the constant b will the motion be critically damped? 2. Relevant equations F = -kx F = mg f = 1/T = ω/2π 3. The attempt at a solution Part A: Fx = -bvx = -0.894⋅vx -kx = F => m⋅a = -k⋅x, and I put the numbers in and got: 0.307⋅9.81 = -2.48⋅x => x = -1.214 m ω = sqrt(k/m), and I put the numbers in and got: ω = 0.452 rad/s Then I tried to calculate vx by: vx⋅(-0.894)=3.0117 => vx = -3.369 m/s I don't know what to do. Thankful for all help I can get!