(me if you can)
a wall is made up of four elements, as follows: ½” wood siding r = 0.81 ½” plywood sheathing r = 0.62 3 ½” fiberglass r = 10.9 ½” sheetrock r = 0.45 (units of r-value are ft2-hr-of/btu)
a. how many btu per hour would be would be transferred through a 1 sq. foot section of the wall if the outside is 50of colder than the inside.
b. in which direction (in or out) would the heat flow? (units of r-value are ft2-hr-ºf/btu)
c. what is the heat transfer through the wall (in btu/hr) if the insulation was not installed?

A3.9 g aluminum foil ball with a charge of +4.1×10−9 c is suspended on a string in a uniform horizontal e⃗ field. the string deviates to the right and makes an angle of 30∘ with the vertical. part a part complete what information about the e⃗ field can you determine for this situation? what information about the field can you determine for this situation? only the magnitude of e⃗ only the direction of e⃗ both the magnitude and the direction of e⃗ none of the above previous answers correct part b determine the magnitude of the electric field. express your answer with the appropriate units. e e = nothing nothing request answer part c determine the direction of the electric field. determine the direction of the electric field. to the right to the left away from you toward you

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.