The timing device in an automobiles intermittent wiper system is based on an RC time constant and utilizes a 0.500-F capacitor and a variable resistor. Over what range must R be made to vary to achieve time constants from 2.00 to 15.0 s?
Chapter 15 Temperature- measure of the average translational kinetic energy per molecule in a substance (C, F, K) Absolute Zero- lowest possible temp that a substance may have – where molecules have min Kinect energy Heat- energy that flows from a substance of higher temp to a substance of lower temp (cal or J) Internal Energy- total of all molecular energies, kinetic plus potential, that are internal to a substance. Specific Heat Capacity- quantity of heat per unit mass required to raise the temp of a substance by 1 C Q=mcT - where q=quantity of heat, c=specific heat, T=change in temp Chapter 16 Conduction- transfer of heat energy by molecular and electron collisions within a substance (especially a solid). Convection- transfer of heat energy in a gas or liquid by means of currents in heated fluid. The fluid moves, carrying energy with it. Radiation- transfer of heat energy by means of electromagnetic waves Terrestrial Radiation- radiation emitted by Earth to space. Newton’s Law of Cooling- rate of loss of heart from a warm object is proportional to the temp difference between the object and its surroundings (applies to heating as well). Greenhouse Effect- Warming of the lower atmosphere by short wave length radiation from the sun that penetrates the atmosphere, absorbed by earth, and is reradiated at longer wavelengths that cannot easily escape earths atmosphere. Solar Constant- 1400 J/m received from the sun each second at the top of earths atmosphere on an area perpendicular to the suns rays; 2 expressed as 1.4 kW/m Solar Power- energy p