ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements. An object is dropped from a platform 400 ft high. Ignoring wind resistance, how long will it take to reach the ground?

25 s
5.0 s
9.0 s
3.5 s

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.