Linear Impulse—Forces Acting Over Time

The SI unit for work is N m, which is aXisAjoulei thus the unit joule (J) is defined as the work done by a 1-N force through a distance of 1 m. 

Students often confuse the concept of work with power. Power represents how fast you want to do the work. It is the time rate of doing work, or said another way, it is the work done divided by the time that it took to petfisrm it. For instance, in Example 10.16, if we want to lift the box in 3 seconds, then the power required is 

Note that 1 J/s is called 1 watt fW). If you wanted to lift the box in 1.5 seconds, then the required power to do this task is 150 J/1.5 s or 100 W Thus, twice as much power is required. It is important to note that the work done in each case is the same however, the power requirement is different. Remember if you want to do work in a shorter time, then you are going to need more power. The shorter the time, the more power required to do that work. We will discuss power and its units in much more detail in Chapter 13. 

7 Linear Impufse—Force Acting Over Time 

Now that you have reached this point in the text 

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Linear Impulse—Force Acting Over Time... 

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