Which of the following explains why international travelers need to use special adapters when plugging a device designed to operate in the u. s. into a wall outlet in europe (i. e., vrms in the u. s. is 120 v, while vrms in europe is 240 v)?
a. the increased voltage causes the device's resistance to increase, and the device won't work.
b. the increased voltage causes the device's resistance to decrease, and the device will overheat.
c. the increased voltage causes an increase in power usage, and the device will overheat.
d. the increased voltage causes a decrease in power usage, and the device won't work.

In a wind tunnel the speed changes as the cross sectional area of the tunnel changes. if the speed in a 6' x 6' square test section is 100 mph, what was the speed upstream of the test section where the tunnel measured 20' x 20'? use conservation of mass and assume incompressible flow. conservation of mass requires that as the flow moves through a path or a duct the product of the density, velocity and cross sectional area must remain constant; i.e., that ova-constant. a model is being tested in a wind tunnel at a speed of 100 mph if the flow in the test section is at sea level standard conditions, what is the pressure at the model's stagnation point? (a) the tunnel speed is being measured by a pitot-static tube connected to a u- tube manometer. what is the reading on that manometer in inches of water? (b) at one point on the model a pressure of 2058 psf is measured. what is the local airspeed at that point?

In a system, when potential energy decreases, then entropy also decreases. true false

Apatient has a history of poor nutrition. he has skin rashes, bleeding gums, and a cut that hasn’t healed in a long time. what vitamin deficiency most likely caused this symptom?