Question 1028027
{{{ h = -16t^2 + v*t + c }}}
Solve for {{{ v }}}:
{{{ v*t =  16t^2 - c + h }}}
{{{ v = 16t + ( h - c ) / t }}}
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The initial height is when {{{ t = 0 }}}
{{{ h(0) = -16*0^2 + v*0 + c }}}
{{{ h(0) = c }}}
given:
{{{ c = 5 }}} ft
{{{ t = 3 }}} sec
{{{ h = 131 }}}
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{{{ v = 16t + ( h - c ) / t }}}
{{{ v = 16*3 + (131 - 5 ) / 3 }}}
{{{ v = 48 + 126/3 }}}
{{{ v = 48 + 42 }}}
{{{ v = 90 }}} ft/sec
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{{{ v = 16t + ( h - c ) / t }}}
When {{{ t = 0 }}}, then {{{ h = c }}} because
you are at the initial height
{{{ ( h-c )/t = 0/0 }}} and
{{{ v = 16*0 + 0/0 }}}
{{{ v = 0/0 }}}
That means you cannot determine the initial
velocity at {{{ t = 0 }}}