Some ancient civilizations used units of measure based on the length of certain seeds. what kind of problems might you expect with such a system ?

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.

Is the portion of the electromagnetic spectrum that has a frequency just above that of visible light.

Which two statements are true about a system? a system is a group of objects analyzed as one unit. energy that moves across system boundaries is conserved there's only one way to define the boundaries of a system all systems are made by humans