A 8.33 mm high chocolate chip is placed on the axis of, and 13.9 cm from, a lens with a focal length of 6.43 cm . If it can be determined, is the chocolate chip's image real or virtual? How high is the image? Express the answer as a positive quantity.

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.