A construction worker is repairing the roof of a house. His hammer of mass 0.50 kg slips from his hand and falls through a basketball hoop to the driveway below. The basketball hoop is 3.1 m above the ground and 5.0 m below the roof where the hammer left the worker's hand. Setting the reference configuration to the roof at the point of the hammer's release, calculate the change in potential energy of the system.

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

At what time will the interfering waves have an amplitudeof zero?

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped