Initial speed = 56mph
Final speed = 35mph
Time taken = 6.7seconds...
Converting the time to hour.. Divide by 3600..
= 6.7/3600
=0.00186hour..
Acceleration = v-u/t
a = 35-56/0.00186
a = -11283.6mph²
The negative sign shows that it decelerated...
V² = u²+2as
(35)² = (56)² + 2×-11283.6×s
Where s is the distance covered within that time...
1225 = 3136 - 22567.2s
22567.2s = 3136-1225
22567.2s = 1911
S = 1911/22567.2
S = 0.08468miles...
But at the end of the question we were made to understand that 1miles = 5280ft
Therefore 0.08468miles = (0.08468×5280)ft
= 447. 11feets...
Which is approximately 447ft.....
Hope this helped.... ?