Question 1134732
Let {{{ k }}} = the constant of proportionality
{{{ F = k*( m/d^2 ) }}}
{{{ d = 4 }}}
{{{ F = 75 }}}
{{{ m = 20 }}}
{{{ 75 = k*( 20/4^2 ) }}}
{{{ k = ( 75*16 )/20 }}}
{{{ k = (75*4)/5 }}}
{{{ k = 15*4 }}}
{{{ k = 60 }}}
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{{{ F = k*( m/d^2 ) }}}
{{{ 200 = 60*( 120/d^2 ) }}}
{{{ d^2 = ( 60*120 )/200 }}}
{{{ d^2 = ( 30*120 )/100 }}}
{{{ d^2 = 36 }}}
{{{ d = 6 }}}