At full power, how long would it take for the car to accelerate from 0 to 62.0 mph ? neglect friction and air resistance.

Given that At full power, the same car can accelerate from 0 to 31 mph in time 1.5 s. How long would it take for the car to accelerate from 0 to 62.0 mph. 
Energy= integral (P×dt) = Pt
therefore;
Since kinetic energy = 1/2 mv^2 = Pt
1/2m(31)² = 1.5 P
  480.5 m  = 1.5 P
        P = 320.33 m
Using the other scenario
1/2m(62)² = 320.33mt
    = 1922 m =320.33 mt
           t = 6.0 sec
 

Wooden , walls ,doors ,support

The correct choice is c