Question 1131229
There is not enough information to answer the question.  If we knew the rate of the constant acceleration "a" caused by application of the brakes (which in this problem is a negative number), we could get the initial speed from the kinematic relation
 
{{{v^2 - v[0]^2 = 2ad}}}
 
{{{v}}} = final speed = {{{0}}} (came to a full stop)
{{{v[0] }}}= initial speed (what you want to solve for)
{{{d }}}= stopping distance = {{{175}}} feet
 
Then
 
{{{v[0] = sqrt(-2ad)}}}  [Remember {{{a}}} is negative, so the argument of the square root is positive.]
 
But as you can see, we need the acceleration {{{a}}}.
 
If we knew the time it took to come to a full stop, we could still answer the question.  Either way, we need more information than just the stopping distance.