A rock sinks straight down the surface of a pond, starting from rest and accelerating at an average rate of 2m/s^2 for the first 3 seconds of its motion. At the 3-second mark, the rock reaches its terminal speed and continues at that speed for the remaining 30 meters of motion. What is the total time it takes for the rock to sink from the surface to the bottom of the lake?

1point) a skydiver weighing 130 lb (including equipment) falls vertically downward from an altitude of 14,000 ft and opens the parachute after 20 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.85|v|0.85|v| when the parachute is closed and is of magnitude 17|v|17|v| when the parachute is open, where the velocity vv 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. find the speed of the skydiver when the parachute opens. speed is 150.6121788 ft/s find the skydiver's height when the parachute opens. height is 2338.98591 ft find the limiting velocity vlvl after the parachute opens. (think about whether this should be positive or negative.) vl=vl= 7.647 ft/s

Asuppose a suitcase has a mass of (m) 30 kg and a net force (n) of 10 kg*m/s. what is the acceleration rate of the suitcasein m/s? show your work to support your answer.

Afigure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 20.9 12000 200 3.33