The question asks "What is the distance the lower spring is extended from its unstretched length?"

what I have done is tried the equation of x=m(g-a)/k where the total mass equals 18.6 and k = 338N/m and a= 3.6 and v=-2.9, I got .34m which then converts to 34cm, but that was wrong, does anyone know how else I could approach this?

To find the distance that the lower spring is extended from its unstretched length, you can apply the principle of Hooke's law. Hooke's law states that the force exerted by a spring is directly proportional to the displacement from its equilibrium position.

In this case, we have the following information:
- Total mass (m) = 18.6 kg
- Spring constant (k) = 338 N/m
- Acceleration (a) = 3.6 m/s^2
- Velocity (v) = -2.9 m/s

To use Hooke's law, we need to consider the net force acting on the system. The net force is given by the equation:

F_net = m * a + k * x,

where F_net is the net force, m is the total mass, a is the acceleration, k is the spring constant, and x is the displacement of the spring.

Since the spring only provides a vertical force, we can write:

m * a = k * x.

Now we can plug in the values and solve for x:

18.6 kg * 3.6 m/s^2 = 338 N/m * x.

Simplifying the equation, we get:

x = (18.6 kg * 3.6 m/s^2) / 338 N/m.

Calculating this, we find:

x ≈ 0.198 m.

Therefore, the distance that the lower spring is extended from its unstretched length is approximately 0.198 meters or 19.8 centimeters.

It seems that your calculation resulted in a different value, so please double-check your calculations to ensure there are no mistakes in the calculations or units used.