FIGURE 6.7 The top diagram (a) shows four cities (A, B, C, and D) at varying elevations above sea level, all with different station pressures. The middle diagram (b) represents sea-level pressures of the four cities plotted on a sea-level chart. The bottom diagram (c) shows isobars drawn on the chart (dark lines) at intervals of 4 millibars. Fig. 6-7, p.147

FIGURE 6. 8 (a) Surface map showing areas of high and low pressure FIGURE 6.8 (a) Surface map showing areas of high and low pressure. The solid lines are isobars drawn at 4-mb intervals. The arrows represent wind direction—the direction from which the wind is blowing. Notice that the wind blows across the isobars. Fig. 6-8a, p.148

Because of the changes in air density, a surface of constant pressure (the shaded gray area) rises in warm, less-dense air and lowers in cold, more-dense air. These changes in elevation of a constant pressure (500-mb) surface show up as contour lines on a constant pressure (isobaric) 500-mb map. p.149

FIGURE 6.8 (b) The upper-level (500-mb) map for the same day as the surface map. Solid lines on the map are contour lines in meters above sea level. Dashed red lines are isotherms in °C. Arrows show wind direction. Notice that, on this upper-air map, the wind blows parallel to the contour lines. Fig. 6-8b, p.148

FIGURE 6.9 The higher water level creates higher fluid pressure at the bottom of tank A and a net force directed toward the lower fluid pressure at the bottom of tank B. This net force causes water to move from higher pressure toward lower pressure. Fig. 6-9, p.150

FIGURE 6.10 The pressure gradient between point 1 and point 2 is4 mb per 100 km. The net force directed from higher toward lower pressure is the pressure gradient force. Fig. 6-10, p.151

Because of the changes in air density, a surface of constant pressure (the shaded gray area) rises in warm, less-dense air and lowers in cold, more-dense air. These changes in elevation of a constant pressure (500-mb) surface show up as contour lines on a constant pressure (isobaric) 500-mb map. p.149

FIGURE 6.8 (b) The upper-level (500-mb) map for the same day as the surface map. Solid lines on the map are contour lines in meters above sea level. Dashed red lines are isotherms in °C. Arrows show wind direction. Notice that, on this upper-air map, the wind blows parallel to the contour lines. Fig. 6-8b, p.148

FIGURE 6.13 On non rotating platform A, the thrown ball moves in a straight line. On platform B, which rotates counterclockwise, the ball continues to move in a straight line. However, platform B is rotating while the ball is in flight; thus, to anyone on platform B, the ball appears to deflect to the right of its intended path. Fig. 6-13, p.152