Arigid, uniform rod of length l and mass m has two small jet engines, each of mass m, fixed at its ends. at the system's center of mass, which is the rod's geometric center, the rod is attached to a fixed pivot, about which it can rotate freely in all directions. take a coordinate system with origin at the pivot and the positive x-axis pointing toward the initial position of jet 1. this means that the initial position of the rod is along the x-axis. #20% part (a) when the rod is in its initial position, jets 1 and 2 provide the respective thrust forces f ai+ bj +ck and f2 di+ej +jk. enter a vector expression for the net initial torque acting on the rod about the pivot, in terms of quantities defined in the problem and the unit vectors i, j, k. -ley2)k (2r-lc2)

Study the diagram showing the range of temperature in the earth’s layers. which temperature most likely corresponds to the asthenosphere? 1,613°c 2,521°c 3,628°c 6,217°c

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?

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?