Calculate the average speed in km/hr of charlie who runs to the store 4 km away in 30 minutes

What happens to the light rays when they hit the specimen?

The necleus of an atom is made up of what subatomic particles?

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.