physics
posted by KB .
When a water gun is ﬁred while being held horizontally at a height of 1.14 m above ground level, the water travels a horizontal distance of 4.50 m. A child, holding the same gun in a horizontal position, slides down a 34.0◦ incline at a con stant speed of 1.98 m/s. The child ﬁres the gun when it is 3.25 m above the ground and the water takes 0.708 s to reach the ground. How far will the water travel horizontally

it takes 0.116 seconds for the water to fall 1.14 meters. So, the horizontal speed of the water is 38.68m/s
the sliding child's horizontal speed is 1.98 cos 34.0° = 1.64 m/s. Add that to the 38.68m/s produced by the gun, and the water's horizontal speed is thus 40.32 m/s.
The water travels 40.32 * 0.708 = 28.55 meters. 
Rats. It takes 0.482 seconds to fall 1.14 meters.
Adjust the horizontal speed accordingly.