AP Physics 2 - Unit 3 Electric Force, Field, Potential Question Which of the following provides evidence that there must be at least two types of electrical charge, but that there is only one type of mass?

I don't really know how to prove there is only one type of mass...

Atotal charge of –6.50 µc is uniformly distributed within a sphere that has a radius of 0.150 m. what is the magnitude and direction of the electric field at 0.300 m from the surface of the sphere? a) 2.89 × 105 n/c, radially inward b) 6.49 × 105 n/c, radially outward c) 4.69 × 105 n/c, radially inward d) 9.38 × 105 n/c, radially outward e) 1.30 × 106 n/c, radially inward

Hydrogen and helium are both members of?

Which accurately compares concave and convex lenses?