How long does it take for the dart to travel the length of the barrel?

Question

The length of the barrel of a primitive blowgun is 1.1 m. Upon leaving the barrel, a dart has a speed of 19 m/s. Assuming that the dart is uniformly accelerated.

Answer 1

Under constant acceleration, the total time and distance can be considered the same as they would be for constant average speed.

Average speed of the dart is 19/2 m/s = 9.5 m/s

Time to travel 1.1 m at 9.5 m/s :
1.1 m / 9.5 m/s = 0.12 s

Answer 2

t = 2x/v = 2*1.1/19 = .116 sec