Review Force and Motion-2

When this cannon fires, cannon and the cannon ball both move, but the cannon ball moves much farther and faster than the cannon. Why?

  1. The cannon ball is smaller.

    No. While smaller size means a little less air resistance, that is not enough to cause the difference.
  2. The wheels on the cannon are stuck.

    No. Even with the wheels moving freely, the cannon ball will still move much faster and much farther.
  3. The cannon ball is round.

    No. While the round shape means a little less air resistance, that is not enough to cause the difference.
  4. The cannon ball weighs less.

    Yes! According to Newton's Second Law of Motion, the more mass an object has, the less it will be affected by a force. Newton's Third Law of Motion tells us that the cannon and the cannon ball will both be pushed by the same amount of force, but since the cannon is much heavier (more mass), it will not move as fast or as far.

    If the cannon was made of very light weight plastic, so that it was much ligher (less mass) than the cannon ball, then the cannon would move farther and faster.



Click to see which state standards this question tests, and which of my videos, experiments, and other resources support that topic.

Florida


SC.5.P.13.3 Investigate and describe that the more mass an object has, the less effect a given force will have on the object's motion.

Utah


UT.3.III.2.b Compare and chart the relative effects of a force of the same strength on objects of different weight (e.g., the breeze from a fan will move a piece of paper but may not move a piece of cardboard).

NGSS


MS-PS2-2 Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.