Which statement is true of forces?
a. forces do not have a specific direction.
b. forces are measured in miles per hour.
c. forces have strength and direction.

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?

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l