Một dây dẫn mảnh được uốn thành một cung tròn bán kính 10cm, góc ở tâm bằng 120 độ. đặt trong không khí, trong dây dẫn có dòng điện cường độ 30A chạy qua. Độ lớn của cảm ứng từ tại tâm của cung tròn là bao nhiêu?

Asher cycles 12 miles in 16 hours. what is his speed?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?

An experiment was performed on a 2-kg block. forces of 5, 10 and 15 newtons respectively were applied to the block for 5 seconds. describe the difference in acceleration between the three trials. a) the final accelerations will all be the same. b) the final acceleration will triple between the first and third trial. c) the final acceleration will be cut by 1/3 from the first to third trial. d) the final acceleration will increase nine time between the first and third trial.