Question 1094357
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1.  It is easy.


2.  Everything is just given to you to write this basic inequality for kinetic energy

        Ek < 600,


    which is the same as 

        {{{(m*v^2)/2  }}} < 600,

    or

        {{{(3*v^2)/2}}} < 600.


    It gives you 

        {{{v^2}}} < {{{(600*2)/3}}} = 400,

    and, after taking the square root from both sides,

        -20 < v < 20.


<U>Answer</U>.  In order for kinetic energy was less than 600 Joules, the speed of the given body must be  in the range from -20 m/s to 20 m/s.
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