How to get more water pressure in shower?

Acatapult is tested by roman legionnaires. they tabulate the results in a papyrus and 2000 years later the archaeological team reads (distances translated into modern units): range = 0.4 km; angle of launch = π/5 rad; landing height = launch height. what is the initial velocity of launch of the boulders if air resistance is negligible?

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m

Acar driving 22.7 m/s on flat ground drives off a 42.3 m high cliff. how much time does it take to reach the ground?