Question 691134
Because you do not know how long it takes to stop the car going 60mph, you need to use this equation:

{{{v[f]^2 = v[i]^2 + 2ad}}}

where {{{v[i] = 60 mph = 60*5280 ft/hr}}}, {{{v[f] = 0}}}, and {{{d = 144ft}}} 

0 = 100,362,240,000 ft^2/hr^2 + (288 ft)a

a = - (100,362,240,000 ft^2/hr^2)/(288 ft) = 348480000 ft/hr^2

For the second car assume the same acceleration that you just calculated, but this time {{{v[i] = 45mph = 45*5280 ft/hr}}} and you calculate d:

0 = 56,453,760,000 ft^2/hr^2 - (696960000 ft/hr^2)d

d = (56,453,760,000 ft^2/hr^2)/(696960000 ft/hr^2) = 81 ft