Spiderman is climbing up a building on one side of a 10-m-wide street when he spots Mary Jane 10 m below, standing on a platform on the other side of the street. The platform is about to explode. Spiderman swings down using his web and grabs Mary Jane, hoping to swing up with her to an open terrace, 5 m above the platform on the same building—where they both would be safe. Will they make it?

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

Write the equation for momentum, first using symbols for the variables, then using words for the variables.

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.