An object attached to a spring undergoes simple harmonic motion modeled by the differential equation d'a + k= 0 where a(t) is the displacement of the mass (relative to equilibrium) at time t, m is the mass of the object, and k is the spring constant. A mass of 7 kilograms stretches the spring 0.75 meters. dt Use this information to find the spring constant. (Use g = 9.8 meters/second) m k= 91.5 The previous mass is detached from the spring and a mass of 19 kilograms is attached. This mass is displaced 0.75 meters above equilibrium (above is positive and below is negative) and then launched with an initial velocity of -0.5 meters/second. Write the equation of motion in the form x(t)= =c cos(wt) + sin(wt). Do not leave unknown constants in your equation. r(t)= = Rewrite the equation of motion in the form z(t) = A cos(Bt-o). Do not leave unknown constants in your equation. Leave as an angle between and 2 a(t) T