A scientist adds different amounts of salt to 5 bottles of water. She then measures how long it takes for the water to boil. What is the responding
variable in this experiment?

A. The time it takes for the water to boil

B. The amount of salt added to the water

C. The kind of bottles used

D. The brand of salt used

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?

True or false: the cycle of seasons on the earth is caused by the tilt of the earth on its axis toward and away from the sun.

The speed of light can be used to measure the