i have a spring with stiffness k. The spring is resting on the ground. Now a mass is kept over the spring. Now the spring deforms by an amount x=mg/k where g is the gravity's acceleration.The force acting on the spring is mg Newtons and the reaction force from the ground is also equal to mg Newtons since this is a statics problem. Now i take the same spring and the mass over it and drop it over another spring of stiffness k1 fixed to the ground. The spring mass has an initial velocity of v.Now how can i calculate the force exerted on this system by the ground due to the impact. After calculating this suppose i find that the force of impact is equal to x times mg can is replace the mass by a mass equal to xm and do a static analysis to find deflection.