How fast can the 150 A current through a 0.250 H inductor be shut off if the induced emf cannot exceed 75.0 V?
PHYSICS 2001 LECTURE 1 NOTES – EXAM 1 Monday, August 22nd Syllabus Day & Sections 1.1-1.4 Section 1.1 – The Nature of Physics - Physics helps to explain how and why the world works as it does - Used to predict outcomes from experimental data - All technology is based in physics o Lasers o Rockets o Transistors o Telecommunication o Etc. Section 1.2 – Units - Units are required for accuracy - Length: Meter o Originally the standard was the distance between 2 marks on a bar of platinum, iridium alloy; the distance measured along the earth’s surface between the north pole and the equator. o Now based on the distance that light travels in a time of 1/229792458 seconds (229,792,458 m/s = speed of light or c) - Mass: Kilogram o Standard based on a cylinder of platinum -iridium o Definition has changed over time; the mass of an object indicates the tendency of the object to continue in motion with a constant velocity. - Time: Second o Originally based on the average time the earth took to com pletely rotate on its axis (86,400)
