Stopping Big Ships ```Name: Matthew H. Status: other Age: N/A Location: N/A Country: N/A Date: N/A ``` Question: I understand that the Titanic ship was travelling at full speed when it noticed the iceberg in its path. How long would it have taken for the Titanic ship to go in reverse and miss the iceberg? Replies: When an object is moving in a straight line, it will continue to move in that direction until and unless some force is applied to the object to cause it to change direction. You can feel this when you are riding in a car at a constant speed -- you do not have any feel that you are moving (if you keep your eyes closed). But if the driver speeds up (you feel pushed back), puts on the brakes (you feel pushed forward), or turns (you feel pulled in the direction opposite to the turning direction). In all these examples, your body is feeling that tendency to keep moving in the same direction, before the change in speed or direction was made. Now, the heavier the object, the greater the force is that causes it to change direction. In the case of the Titanic, the iceberg was so heavy it would not allow the ship to change direction, so something has to give (break) and it did. You can experience the same effect if you jump off a chair onto the floor. The floor does not move so your body has to absorb the shock of having to suddenly stop. This is also why parachutes are used when people jump out of airplanes. It is a much more difficult problem to actually calculate how much force and how much time is required. That depends upon the details of the particular example. But it is more important to understand the rules. Calculating the numbers will follow when you learn more math, but the principles do not change. Vince Calder Click here to return to the Physics Archives

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