Lake Mead, the reservoir above Hoover Dam, has a surface area of approximately 640 km2. The top 1 meter of water in the lake weighs about 6.3 x 1012 N. The dam holds that top layer of water 220 m above the river below, What is the potential energy of the top 1 m of water in Lake Mead. Group of answer choices

140800 j

2156 j

1.38 x 10^15 j

14367.3 j

Several students in the group made comments to the coach about the back pack. which student has the correct analysis of the forces and motion of the back pack?

The density of a substance is 4.0 g/cm3. if a sample of the substance has a volume of 25 cm3 then what is the mass

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.