A student is given a sample of matter and asked to determine whether it is an element.

Determine the critical height h of the water level that causes the concrete gravity dam to be on the verge of tipping over due to water pressure. the density of concrete is ρc = 2.40 mg/m3. suppose that hd = 38 m. hint: work the problem using a 1-m width of the dam.

With i really need the correct answer!

Aleaky 10-kg bucket is lifted from the ground to a height of 15 m at a constant speed with a rope that weighs 0.7 kg/m. initially the bucket contains 45 kg of water, but the water leaks at a constant rate and finishes draining just as the bucket reaches the 15-m level. find the work done. (use 9.8 m/s2 for g.) show how to approximate the required work by a riemann sum. (let x be the height in meters above the ground. enter xi* as xi.) lim n → ∞ n (9.8)(45−3 xi) i = 1 δx express the work as an integral. 0 dx evaluate the integral. (round your answer to the nearest integer.) j