0.21kg pine cone falls 14 m to the ground, where it lands with a speed of 13 m / s. (a) with what speed would the pine cone have landed if there had been no air resistance? (b) did air resistance do positive work, negative work, or zero work on the pine cone? explain

Aray diagram for a refracted light day is shown. what does the dashed line represent

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.

Consider two metallic rods mounted on insulated supports. one is neutral, the other positively charged. you bring the two rods close to each, but without contact, and briefly ground the the neutral rod by touching it with your hand. show answer correct answer what would be resulting charge (if any) on the initially neutral rod