As shown in the diagram, a 4800-kg cable car is descending a high hill. A counterweight of mass 4600 kg on the other side of the hill aids the brakes in controlling the cable car's speed.
The rolling friction of both the cable car and the counterweight are negligible. How much
braking force does the cable car need to descend at constant speed?

Will you chech and finish these for me, because i am stumped with them.

Ascientific blank must be testable and capable of being proven false?

Acarpenter builds an exterior house wall with a layer of wood 2.9 cm thick on the outside and a layer of styrofoam insulation 2.3 cm thick on the inside wall surface. the wood has k=0.080w/(m⋅k), and the styrofoam has k= 0.010 w/(m⋅k). the interior surface temperature is 19.0 ∘c , and the exterior surface temperature is -15.0 ∘c . a.)what is the temperature at the plane where the wood meets the styrofoam? celsius b.)what is the rate of heat flow per square meter through this wall? /m^2