How to find Va, Vb, Vc, Vd and R1,R2,R4,R6 current?

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

Ablock of steel has a density of 0.29lbs per cubic inch. if the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight? a. 0.29lbs b. 0.58lbs c. 0.87lbs d. 1lbs

The energy of a photon was found to be 3.38 × 10–19 j. planck’s constant is 6.63 × 10–34 j • s. which color of light corresponds to this photon?