Consider a 1000-w iron whose base plate is made of 0.5-cm-thick aluminum alloy (ρ = 2770 kg/m3, cp = 875 j/kg·°c, α = 7.3x10-5 m2/s). 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. taking the heat transfer coefficient at the surface of the base plate to be 12 w/m2·°c and assuming 85 percent of the energy generated in the resistance wires is transferred to the plate, determine how long it will take for the plate temperature to reach 140°c. is it realistic to assume the plate temperature to be uniform at all times? note: use an energy balance and come up with a differential equation to solve for this problem.

When you turn on a battery-operated device, an electrical circuit is

The coulomb's law explains which of the following? select all the force between two charged objects is inversely proportional to the charge on each object. the force between two charged objects is directly proportional to the charge on each object. the force between two charged objects is directly proportional to the distance separating them. the force between two charged objects is inversely proportional to the square of the distance separat coulomb's law is similar to newton's 2nd law. if the force between two objects is f and the charge on both objects is doubled, the new force between the would now be 2f. if the force between two objects is 2f and the distance separating them is doubled, the new force between the objects would now o the be zf.

1kg of water needs to recieve 4200j of energy to go from 90 degrees to 91 degrees. what is the specific heat capacity of water? what are the units?