2. what does the ph scale measure?
the strength of hydrogen lons.
the concentration of hydrogen ions.
the concentration of an acid.
the strength of an acid.
ph
6096

Does work output exceed work input when a machine is used? a) yes, it does, as machines create energy. b) it depends on the type of machine used. c) no, it doesn’t, as machines are inefficient. d) no, it doesn’t, as machines cannot create energy.

An object's buoyant force and weight mean the same thing. a. trueb. false

Abookcase has a mass of 38 kg and the coefficient of friction between it and the floor is 0.82 what is the maximum force of friction between the bookcase and the floor a 372n b 305n c 412n d 449n