Here's how to convert the speed of the projectile from feet per second (fps) to kilometers per hour (km/h):

Conversion Factors:

* 1 foot = 0.3048 meters

* 1 meter = 0.001 kilometers

* 1 hour = 3600 seconds

Calculation:

1. Convert feet to meters: 1429 fps * 0.3048 meters/foot = 435.43 meters/second

2. Convert meters to kilometers: 435.43 meters/second * 0.001 kilometers/meter = 0.43543 kilometers/second

3. Convert seconds to hours: 0.43543 kilometers/second * 3600 seconds/hour = 1569.55 km/h

Therefore, the speed of the projectile is approximately 1569.55 km/h.