How do you find the volume of a lead ball if the mass is 454 grams?

Which type of microscope would allow the viewer to see ribosomes inside a cell?

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s. calculate eddy’s power rating

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.