Ablow-back device for a diameter d = 0.22 (in) under p = 24000 [lb/in? ) pressure connects a breech block with a mass m = 1/2 (slug/32.2] to the origin, where x = 0, by a spring, which exerts a force of 3 (lb) when the breech block is moved back by 1.5 in), so that the spring constant is k=3/1.5 lb/in. friction is so small that the measuring instruments at hand do not detect any friction (3.1) find a formula for the force on the breech block in terms of pressure, diameter, and spring. (3.2) find an algebraic formula for the acceleration x(t) of the breech block at time t, for 0 0 when x(ti) = 0. (when is the breech block back at 0? )