# The average weight of an American male was 166 pounds.  By 2002, the average weight of an American male increased to 191 pounds.    Using Newton's Second Law of Motion, describe how the increase of the average weight will impact the performance and safety of a roller coaster Newtown's Second Law of Motion describes the relationship between the amount of force on an object, the objects mass and acceleration. The equation for this is `F=MA` . This means that the amount of force on an object is equal to the mass of the object multiplied by the acceleration. An increase in acceleration or mass means an increase in force.

Using this knowledge, we can see how the increase of the average weight of American males can greatly impact roller coaster safety. The main method of propulsion for a roller coaster car is gravity. The acceleration from gravity stays relatively constant at about 9.8 meters per second squared (`m/sec^2` ). While the actual acceleration of the first drop of the roller coaster will be considerably less because it is not a straight drop, we will use this number for the example of what happens as passenger mass increases.

Force for the initial American male weight (converted to kg):

`F=MA`

`F=(75.3kg)(9.8m/sec^2)`

`F=737.94N`

Force for the 2002 average American male weight (converted into kg):

`F=MA`

`F=(86.6kg)(9.8m/sec^2)`

`F=848.68N`

There is a 110.74 N difference in force for one person. When considering roller coaster safety, also consider also that a roller coaster car has many people in it, increasing the overall mass of the car by several times that amount. The increase in force can have negative impacts on the passengers and will make more advanced deceleration systems during the coasting phase of the roller coaster necessary. The cars themselves will have to be structurally capable of withstanding the additional force. Also, tracks will have to be monitored for signs of early wear due to the additional force, especially around curves where it will be more pronounced due to the change in direction.