Star a has an apparent magnitude of ‒1.5 and is 12.7 light years from earth. star b has an apparent magnitude of 0.4 and is 15.6 light years from earth. explain why apparent magnitude should not be used to determine which star is brighter. identify the additional information you would need in order to determine which star should be described as the brighter star.

An observer that stands still as the electron moves by him, will observe

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.

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)