Ablock with mass m = 0.4 kg oscillates with amplitude a = 0.4 m at the end of a spring with force constant k = 15 n/m on a frictionless, horizontal surface. rank the periods of the following oscillating systems from greatest to smallest. if any periods are equal, show their equality in your ranking. (use only "> " or "=" symbols. do not include any parentheses around the letters or symbols.)
(a) the system is as described above.
(b) the amplitude is changed to 1.6 m.
(c) the mass is changed to 1.6 kg.
(d) the spring now has a force constant of 30 n/m.
(e) a small resistive force is added so the motion is underdamped.

Find the momentum for a 2.6-kg brick parachuting straight downward at a constant speed of 8.4 m/s .

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.