As a young boy swings a yo-yo parallel to the ground above his head. The yo-yo has a centripetal acceleration of 250 m/s? If the yo-yo's string is 0.50 m long, what is the yo-yo's tangential speed?

Which safety measures should you follow during a thunderstorm? check all that apply. (a) avoid touching anything that conducts electricity. (b) avoid touching a person who has been struck by lightning. (c) go outside. (d) keep your computer turned off. (e) stay out of water. (f) stay inside.

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.

Acalorimeter uses the principle that thermal energy flows from hotter material to colder material until both reach the same