One the first observations that suggested his nuclear model of the atom to rutherford was that several alpha particles got scattered by metal foils into the backward hemisphere, 7/2 < 0 < r - an observation that was impossible to explain on the basis of rival atomic models, but emerged naturally from the nuclear model. in an early experiment, geiger and marsden measured the fraction of incident alphas scattered into the backward hemisphere off a platinum foil. by integrating the rutherford cross section (14.33) over the backward hemisphere, show that the cross section for scattering with 6 > 90° should be 47 t co (e). using the following numbers, predict the ratio ns,(0 > 90°)/nin,: thickness of platinum foil ti 3 pm, density = 21.4 gram/cm3 , atomic weight = 195, atomic number = 78, energy of incident alphas = 7.8 mev. compare your answer with their estimate that "of the incident a particles about 1 in 8000 was reflected" (that is, scattered into the backward hemisphere). small as this fraction is, it was still far larger than any rival model of the atom could explain.

Agas is contained in a vertical, frictionless piston–cylinder device. the piston has a mass of 3.2 kg and a cross-sectional area of 35 cm2. a compressed spring above the piston exerts a force of 190 n on the piston. if the atmospheric pressure is 95 kpa, determine the pressure inside the cylinder.

The bubba chump shrimp company processes and packages shrimp for sale to wholesale seafood distributors. the shrimp are transported to the main plant by trucks that carry 1,000 pounds (lb) of shrimp. once the continuous flow processing of the shrimp begins, no inventory is allowed in buffers due to spoilage and all of the shrimp must be processed within 12 hours to prevent spoilage. the processing begins at the sorter, where the trucks dump the shrimp onto a conveyor belt that feeds into the sorter, which can sort up to 500 lb per hour. the shrimp then proceed to the desheller, which can process shrimp at the rate of 400 lb per hour. however, after 3 hours and 45 minutes of processing, the desheller must be stopped for 15 minutes to clean out empty shrimp shells that have accumulated. the veins of the shrimp are then removed in the deveining area at a maximum rate of 360 lb per hour. the shrimp proceed to the washing area, where they are processed at 750 lb per hour. finally, the shrimp are packaged and frozen. what is the daily process capacity of the processing plant (excluding the packaging and freezing)?

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.