The fastest time ever run at Pikes Peak is 7:57. That’s way too long. If we removed all the curves, making a straight line from top to bottom, how quickly could a Redeye reach the top?

ProTips:
Slope of 6.4%
Redeye top speed 203 mph
A stock Redeye has a peak acceleration of over 1g. Assume this Redeye will accelerate at an average of .091 g (2.93 ft/s2)
The 12.42 mile long Pike’s Peak course has over 156 turns

What you might need:
(unit conversions)
A smart friend
Some kinematic equations:
d=v^2/2a
t=v_f/a
t=d_remaining/v_f

Respuesta :

Answer:

  4 minutes 31.06 seconds

Step-by-step explanation:

We can start by converting the speed and distance to units compatible with the acceleration.

  12.42 mi = (12.42 mi)(5280 ft/mi) = 65,577.6 ft

  203 mi/h = (203 mi/h)(22/15 ft/s)/(1 mi/h) = 297 11/15 ft/s = 4466/15 ft/s

Then the time taken to reach top speed will be ...

  t = v_f/a = (4466/15 ft/s)/(2.93 ft/s^2) = 101.615 s

The distance covered while reaching top speed is ...

  d = v^2/(2a) = (4466/15 ft/s)^2/(2(2.93 ft/s^2)) = 15,127.157 ft

So, the remaining distance is ...

  d_remaining = 65,577.6 ft -15,127.157 ft = 50,450.443 ft

And the time required to cover that distance is ...

  t = d_remaining/v_f = (50,450.443 ft)/(4466/15 ft/s) = 169.448 s

The total time taken for acceleration and cruise to the top is ...

  101.615 s + 169.448 s = 271.064 s ≈ 4 minutes 31.06 seconds

_____

We have assumed that the rocket's acceleration is fully applied in the direction of travel. We have to assume that the acceleration due to gravity is otherwise accounted for.