Which statement best describes what happens when air warms in the atmosphere? A. Air condenses and rises up.
B. Air expands and rises up.
C. Air expands and sinks down.
D. Air condenses and sinks down.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.