Old naval ships fired 15 kg cannon balls from a 210kg cannon. It was very important to stop the recoil of thecannon, since otherwise the heavy cannon would go careening acrossthe deck of the ship. In one design, a large spring with springconstant 2.0×104 N/m was placed behind thecannon. The other end of the spring braced against a post that wasfirmly anchored to the ship's frame.
What was the speed of the cannon ball if the spring compressed50 cm when the cannon was fired?