Three batteries are connected in series so that the total voltage is 54 volts. the voltage of the first battery is twice the voltage of the second and 1/3 the voltage of the third battery. find the actual voltage of each battery.

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.

You can decrease the resistance of a length of wire by

Which of the following forces require physical contact? tension air resistance friction magnetic force applied force