Abag of sand originally weighing 144 lb was lifted at a constant rate. as it rose, sand also leaked out at a constant rate. the sand was half gone by the time the bag had been lifted to 10 ft. how much work was done lifting the sand this far? (neglect the weight of the bag and lifting equipment.)

Abird sitting high in a tree is an example of what type of wnergy

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

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds