A block of mass m1=5.0 kg moves in uniform circular motion with a radius of 3.0m on a frictionless table. The block is connected by a string and a pulley to another block of mass m2 which hangs through a hole in the center of the table, as shown in the figure. If block 1 is moving at a speed of v=2.0 m/s, what is the mass of block 2?

Ahollow metal sphere has 6 cm and 11 cm inner and outer radii, respectively. the surface charge density on the inside surface is −100nc/m2. the surface charge density on the exterior surface is:

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)

It is really hard for me right know