5 A boy of mass 40 kg and a girl of mass 30 kg play on a see-saw of negligible weight. If the boy sits 270 cm from
the pivot of the see-saw, where must the girl sit to make it
balance?

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

This is the substance(s) formed in a chemical reaction.

The rocket is fired vertically and tracked by the radar station shown. when θ reaches 66°, other corresponding measurements give the values r = 32700 ft, r¨ = 85 ft/sec2, and θ˙ = 0.019 rad/sec. calculate the magnitudes of the velocity and acceleration of the rocket at this position.