Q. A new car is tested on a 250 diameter track. If the car speeds up at a steady 1.7m/s^2 , how long after starting is the magnitude of its centripetal acceleration equal to the tangential acceleration?

Q. Old naval ships fired 11 kg cannon balls from a 250 kg cannon. It was very important to stop the recoil of the cannon, since otherwise the heavy cannon would go careening across the deck of the ship. In one design, a large spring with spring constant 2.0×10^4 N/m was placed behind the cannon. The other end of the spring braced against a post that was firmly anchored to the ship's frame.