An object attached to a spring undergoes simple harmonic motion modeled by the differential equation md2xdt2+kx=0\displaystyle {m}\frac{{{d}^{{2}}{x}}}{{{\left.{d}{t}\right.}^{{2}}}}+{k}{x}={0} where x(t)\displaystyle {x}{\left({t}\right)} is the displacement of the mass (relative to equilibrium) at time t\displaystyle {t}, m\displaystyle {m} is the mass of the object, and k\displaystyle {k} is the spring constant. A mass of 5\displaystyle {5} kilograms stretches the spring 0.65\displaystyle {0.65} meters.

Use this information to find the spring constant. (Use g=9.8\displaystyle {g}={9.8} meters/second2)

k=\displaystyle {k}=  

The previous mass is detached from the spring and a mass of 17\displaystyle {17} kilograms is attached. This mass is displaced 0.3\displaystyle {0.3} meters below equilibrium and then launched with an initial velocity of 2\displaystyle {2} meters/second. Write the equation of motion in the form x(t)=c1cos(ωt)+c2sin(ωt)\displaystyle {x}{\left({t}\right)}={c}_{{1}}{\cos{{\left(\omega{t}\right)}}}+{c}_{{2}}{\sin{{\left(\omega{t}\right)}}}. Do not leave unknown constants in your equation.

x(t)=\displaystyle {x}{\left({t}\right)}=  

Rewrite the equation of motion in the form x(t)=Asin(ωt+ϕ)\displaystyle {x}{\left({t}\right)}={A}{\sin{{\left(\omega{t}+\phi\right)}}}. Do not leave unknown constants in your equation.

x(t)=\displaystyle {x}{\left({t}\right)}=