Question 1144179
Ave velocity is [ total displacement ] / [ total travel time ]
In this case, displacement is the same as distance traveled.
{{{ t[1] = 20/40 }}}
{{{ t[1] = 1/2 }}} hr
and
{{{ t[2] = 1/4 }}} hr
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{{{ d[1] = 20 }}} mi
and
{{{ d[2] = 60*(1/4) }}}
{{{ d[2] = 15 }}} mi
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Ave. vel. = {{{ ( 20 + 15 ) / ( 1/2 + 1/4 ) }}}
Ave. vel. = {{{ 35 / ( 3/4 ) }}}
Ave. vel. = {{{ 26.25 }}} mi/hr