What is the density of a substance that has a volume of 30ml and a mass of 20g?

Along, straight wire with 3.0 a current flowing through it produces magnetic field strength 1.0 t at its surface. if the wire has a radius r, where within the wire is the field strength equal to 36.0% of the field strength at the surface of the wire? assume that the current density is uniform throughout the wire

If 2 moles of co_2 at 2l and 500k are expanded reversibly to 20l, more work can be obtained from an adiabatic process than from an isothermal process. is the above statement true or false?

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline