How are the states of matter changed by the introduction of heat?

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?

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

How many times did thomas edison mess up the light bulb