Comparing these expressions with those above, we see that T aB/A=aA/B One important observation is that, whenever the moving system, say A, has a constant velocity relative to the fixed system, O, then the acceleration seen by the two observers is the same, i. e if aA=0, then aB=aB/A. We shall see that this broadens the application of Newton's second law to systems which have a constant absolute velocity Example Glider in cross wind Consider a glider flying at the edge of a cloud. The glider is flying horizontally, and the cloud, which is below the glider, is stationary with respect to the ground. At the altitude of the glider fight, there is a wind locity, vu, of magnitude 52 knots, as shown in the sketch 210° 240°270 30° 3600 North Edge of Cloud The glider, on the other hand, is flying at a speed UG/w relative to the local wind. In order to determine the speed of the glider with respect to the ground, we consider a reference frame moving with the wind spee and write G=Uw t ug/u or graphically G By looking at the scaled diagram below, we can verify the following situations. If the glider flies with a heading of 330 and a speed (relative to the wind)of 90 knots, it will stay at the edge of the cloud with aComparing these expressions with those above, we see that rB/A = −rA/B, vB/A = −vA/B, aB/A = −aA/B , as expected. One important observation is that, whenever the moving system, say A, has a constant velocity relative to the fixed system, O, then the acceleration seen by the two observers is the same, i.e., if aA = 0, then aB = aB/A. We shall see that this broadens the application of Newton’s second law to systems which have a constant absolute velocity. Example Glider in cross wind Consider a glider flying at the edge of a cloud. The glider is flying horizontally, and the cloud, which is below the glider, is stationary with respect to the ground. At the altitude of the glider flight, there is a wind velocity, vw, of magnitude 52 knots, as shown in the sketch. North Edge of Cloud Cloud The glider, on the other hand, is flying at a speed vG/w relative to the local wind. In order to determine the speed of the glider with respect to the ground, we consider a reference frame moving with the wind speed and write vG = vw + wG/w, or graphically, By looking at the scaled diagram below, we can verify the following situations. If the glider flies with a heading of 330o and a speed (relative to the wind) of 90 knots, it will stay at the edge of the cloud with a 3