Es and Moion Assessment (Luncn) 12of25
While waiting for the bus you take a seat on the metal bench at the bus stop. The bench feels very cold to you. Why? (AKS 7c DOK 2)
A The warmth in your hands is being transferred to the bench via conduction.
OB. The warmth in your hands is being transferred to the bench via convection.
Oc. The coldness of the bench is being transferred to your hands via conduction.
OD. The coldness of the bench is being transferred to your hands via convection.

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i. e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).