While watching ocean waves at the dock of the bay, Otis notices that 10 waves pass beneath him in 30 seconds. he also notices that the crests of successive waves exactly coincide with the posts that are 5 meters apart. What is the period of the waves

Several processes form metal ore. match each process to its description. volcanic activity weathering hydrothermal energy rocks break down as they interact with air and water. arrowright density differences and other factors cause metals to concentrate in igneous rocks. arrowright seawater heats up from contact with hot rock, and metals dissolve in it. the water rises and contacts cooler water, causing metal ores to settle on the ocean floor. arrowright

Apatient has a history of poor nutrition. he has skin rashes, bleeding gums, and a cut that hasn’t healed in a long time. what vitamin deficiency most likely caused this symptom?

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?