Consider four small spheres A, B, C, and D. Sphere B is positively charged. B attracts A and C but repels D. A and C repel one another. What sign of electrical charge is on A, C, and D?

You have been called to testify as an expert witness in a trial involving a head-on collision. car a weighs 1515 lb and was traveling eastward. car b weighs 1125 lb and was traveling westward at 44.0 mph. the cars locked bumpers and slid eastward with their wheels locked for 22.5 ft before stopping. you have measured the coefficient of kinetic friction between the tires and the pavement to be 0.750 . how fast (in miles per hour) was car a traveling just before the collision? (this problem uses english units because they would be used in a u. s. legal proceeding.)

The radius of an atom is closest in size to a

Since the energy was not raising the temperature of the water during these segments, what was the energy used to do instead? your answer must include an explanation of what is happening to the molecules.