What does it mean to say that science is a “systematic” process?

What type of electromagnetic wave is used in security pens? a. x-rays c. microwaves b. visible light d. ultraviolet radiation select the best answer from the choices provided

Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon

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.