Why did physicists expect a hot filament to give off ultraviolet light as its temperature increased? a. they thought that light existed as particles of various energies. b. they thought that light could be absorbed or emitted only in specific-sized chunks. c. they thought that matter could emit only certain frequencies of light. d. they thought that as the energy increased, the frequency of light would increase.

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