posted by James Caulfield .
17. A shell having a mass of 25kg is fired horizontally eastward from a cannon with a velcoity of 500m/s. If the mass of the cannon is 1000kg, what is the magnitude and direction of the velocity of recoil?
18. A bomb having a mass of 8kg explodes into two pieces that fly out horizontally in opposite directions. One piece is found to have a mass of 6kg and the other a mass of 2kg. What was the ratio of speeds with which the two pieces moved apart immediately after the explosion occurred?
20. When a car of mass 2.0 * 10^3 moving at 9m/s collides head on with a second car having a mass of 1.5 * 10^3, the cars lock and come to rest at point of collision. (a)What was the momentum of the second car before the collision? (b) what was the velocity of the second car before the collision?