Aweight suspended from a spring is seen to bob up and down over a distance of 39 cm twice each second. what is its frequency? answer in units of hz.

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

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?