A45-kg box containing a new bicycle has just arrived in the front porch and two brothers are fighting over it. the first brother pulls with a five of 52 n, while the second brother pulls on the opposite direction with a force of 125 n. what is the minimum coefficient of static friction that will prevent the box from moving?

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference

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.

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?