If a object has a mass of 20g and a volume of 3.5cm3 what is the density

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

Energy flows from the producer level to the level. is called

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.