A hydroelectric dam holds back a lake of surface area 3.0�106m2 that has vertical sides below the water level. The water level in the lake is 150 m above the base of the dam. The density of water is 1000 kg/m3.

-How much total energy is stored in the lake? Take the gravitational potential energy to be zero at the base of the dam. (Hint: Break the lake up into infinitesimal horizontal layers of thickness dy, and integrate to find the total potential energy.) Express your answer using two significant figures.

-Express your answer in kilowatt-hours. Express your answer using two significant figures.

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

Part a determine the magnitude of the x component of f using scalar notation. fx f x = nothing lb request answer part b determine the magnitude of the y component of f using scalar notation. fy f y = nothing lb request answer part c determine the magnitude of the z component of f using scalar notation. fz f z = nothing lb request answer provide feedback figure1 of 1a force vector acting on a ring attached to the ground is shown in the xyz space together with its x, y, and z components lying on the corresponding positive axes. the ring is located at the origin. force f is located in the first octant. f makes an angle of 60 degrees with its x component and an angle of 45 degrees with its y component. a force vector acting on a ring attached to the ground is shown in the xyz space together with its x, y, and z components lying on the corresponding positive axes. the ring is located at the origin. force f is located in the first octant. f makes an angle of 60 degrees with its x component and an angle of 45 degrees with its y component.

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.