Amotorbike engine can develop a power of 9 w in order to keep a constant velocity of 30 m/s. what is the pushing force?

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?

What is the length x of the side of the triangle below? (hint: use the cosine function)

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?